Delivery of hydrophobic active agent particles

ABSTRACT

Embodiments of the invention include drug delivery coatings and devices including the same. In an embodiment, the invention includes a drug delivery coating including a polymeric layer. The polymeric layer can include a hydrophilic outer surface. The coating can also include a matrix contacting the hydrophilic outer surface. The matrix can include a particulate hydrophobic therapeutic agent and a cationic agent. The polymeric layer can further include a hydrophilic polymer having pendent photoreactive groups and a photo-crosslinker including two aryl ketone functionalities. Other embodiments are also included herein.

This application is a continuation of U.S. application Ser. No.16/847,272, filed Apr. 13, 2020, issuing as U.S. Pat. No. 11,519,440 onDec. 20, 2022, which is a continuation of U.S. application Ser. No.15/850,010, filed Dec. 21, 2017, now U.S. Pat. No. 10,617,793, issuedApr. 14, 2020, which is a continuation of U.S. application Ser. No.14/609,270, filed Jan. 29, 2015, now U.S. Pat. No. 9,861,727, issuedJan. 9, 2018, which is a continuation-in-part application of U.S.application Ser. No. 13/793,390, filed Mar. 11, 2013, now U.S. Pat. No.10,213,529, issued Feb. 26, 2019, which is a continuation-in-part ofU.S. application Ser. No. 13/469,844, filed May 11, 2012, now U.S. Pat.No. 9,757,497, issued Sep. 12, 2017, which claims the benefit of U.S.Provisional Application No. 61/488,582, filed May 20, 2011, the contentof all of which is herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to devices and coatings for devices suchas medical device. More specifically, the present invention relates todevices and coatings for devices including hydrophobic active agentparticles.

BACKGROUND OF THE INVENTION

The vascular system of the human is subject to blockage due to plaquewithin the arteries. Partial and even complete blockage of arteries bythe formation of an atherosclerotic plaque is a well-known and frequentmedical problem. Frequently, such blockage occurs in the coronaryarteries. Blockages may also occur secondary to past treatment ofspecific sites (restenosis—such as that stemming from rapidly dividingsmooth muscle cells). In addition, blockages can also occur in thecontext of peripheral arteries.

Blockages may be treated using atherectomy devices, which mechanicallyremove the plaque; hot or cold lasers, which vaporize the plaque;stents, which hold the artery open; and other devices and proceduresdesigned to increase blood flow through the artery.

One common procedure for the treatment of blocked arteries ispercutaneous transluminal coronary angioplasty (PTCA), also referred toas balloon angioplasty. In this procedure, a catheter having aninflatable balloon at its distal end is introduced into the coronaryartery, the deflated, folded balloon is positioned at the stenotic site,and then the balloon is inflated. Inflation of the balloon disrupts andflattens the plaque against the arterial wall, and stretches thearterial wall, resulting in enlargement of the intraluminal passagewayand increased blood flow. After such expansion, the balloon is deflated,and the balloon catheter removed. A similar procedure, calledpercutaneous transluminal angioplasty (PTA), is used in arteries otherthan coronary arteries in the vascular system. In other relatedprocedures, a small mesh tube, referred to as a stent is implanted atthe stenotic site to help maintain patency of the coronary artery. Inrotoblation procedures, also called percutaneous transluminal rotationalatherectomy (PCRA), a small, diamond-tipped, drill-like device isinserted into the affected artery by a catheterization procedure toremove fatty deposits or plaque. In a cutting balloon procedure, aballoon catheter with small blades is inflated to position the blades,score the plaque and compress the fatty matter into the artery wall.During one or more of these procedures, it may be desirable to deliver atherapeutic agent or drug to the area where the treatment is occurringto prevent restenosis, repair vessel dissections or small aneurysms orprovide other desired therapy.

Additionally, it may be desirable to transfer therapeutic agents toother locations in a mammal, such as the skin, neurovasculature, nasal,oral, the lungs, the mucosa, sinus, the GI tract or the renal peripheralvasculature.

SUMMARY OF THE INVENTION

Embodiments of the invention include drug delivery coatings and devicesincluding the same. In an embodiment, the invention includes a drugdelivery coating including a polymeric layer. The polymeric layer caninclude a hydrophilic outer surface. The coating can also include amatrix contacting the hydrophilic outer surface. The matrix can includea particulate hydrophobic therapeutic agent and a cationic agent. Thepolymeric layer can further include a hydrophilic polymer having pendentphotoreactive groups and a photo-crosslinker including two aryl ketonefunctionalities. Other embodiments are also included herein.

In an embodiment, the invention includes a drug delivery deviceincluding a substrate; a hydrophilic polymer layer disposed on thesubstrate; and coated therapeutic agent particles disposed on thehydrophilic polymer layer, the coated therapeutic agent particlescomprising a particulate hydrophobic therapeutic agent; and a cationicagent disposed over the particulate hydrophobic therapeutic agent.

In an embodiment, the invention includes a drug delivery coatingincluding a polymeric layer, the polymeric layer comprising ahydrophilic surface; coated therapeutic agent particles disposed on thehydrophilic surface, the coated therapeutic agent particles comprising aparticulate hydrophobic therapeutic agent core; and a cationic agentsurrounding the particulate hydrophobic therapeutic agent core, thecationic agent exhibiting affinity for the surface of a cell membrane.

In an embodiment, the invention includes a method of forming a drugdelivery coating including applying a hydrophilic base coat onto asubstrate; forming coated therapeutic agent particles, the coatedtherapeutic agent particles comprising a particulate hydrophobictherapeutic agent and a cationic agent disposed over the particulatehydrophobic therapeutic agent core; and applying the coated therapeuticagent particles to the substrate.

This summary is an overview of some of the teachings of the presentapplication and is not intended to be an exclusive or exhaustivetreatment of the present subject matter. Further details are found inthe detailed description and appended claims. Other aspects will beapparent to persons skilled in the art upon reading and understandingthe following detailed description and viewing the drawings that form apart thereof, each of which is not to be taken in a limiting sense. Thescope of the present invention is defined by the appended claims andtheir legal equivalents.

BRIEF DESCRIPTION OF THE FIGURES

The invention may be more completely understood in connection with thefollowing drawings, in which:

FIG. 1 is a schematic cross-sectional diagram of a coating in accordancewith an embodiment herein.

FIG. 2 is a schematic cross-sectional diagram of a coating in accordancewith an embodiment herein.

FIG. 3 is a schematic cross-sectional diagram of a coating in accordancewith an embodiment herein.

FIG. 4 is a schematic cross-sectional diagram of a coating in accordancewith an embodiment herein.

FIG. 5 is a schematic diagram of a device in accordance with anembodiment herein.

FIG. 6 is a schematic cross-sectional diagram of a coating in accordancewith various embodiments herein.

FIG. 7 is a schematic cross-sectional diagram of a coating in accordancewith various embodiments herein.

FIG. 8 is a schematic cross-sectional diagram of a coating in accordancewith various embodiments herein.

FIG. 9 is a schematic cross-sectional diagram of a coating in accordancewith various embodiments herein.

FIG. 10 is a graph of the adhesion of microparticles to MATRIGEL® plateswith no excipient and using polyethyleneimine (PEI) as an excipient, andpolyacrylic acid (PAA).

While the invention is susceptible to various modifications andalternative forms, specifics thereof have been shown by way of exampleand drawings, and will be described in detail. It should be understood,however, that the invention is not limited to the particular embodimentsdescribed. On the contrary, the intention is to cover modifications,equivalents, and alternatives falling within the spirit and scope of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of the present invention described herein are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather, the embodimentsare chosen and described so that others skilled in the art canappreciate and understand the principles and practices of the presentinvention.

All publications and patents mentioned herein are hereby incorporated byreference. The publications and patents disclosed herein are providedsolely for their disclosure. Nothing herein is to be construed as anadmission that the inventors are not entitled to antedate anypublication and/or patent, including any publication and/or patent citedherein.

As described above, in association with procedures such as percutaneoustransluminal coronary angioplasty (PTCA), percutaneous transluminalangioplasty (PTA), and the like, it can be desirable to deliver atherapeutic agent or drug to the area where the treatment is occurringto prevent restenosis, repair vessel dissections or small aneurysms orprovide other desired therapy. One approach for accomplishing this is todeliver a therapeutic agent (or active agent) to the desired tissue siteusing a drug delivery device such as a drug eluting balloon catheter ora drug-containing balloon catheter.

Drug delivery coatings for certain medical applications desirablyexhibit various properties. By way of example, in the context of a drugeluting balloon catheter or a drug-containing balloon catheter, thecoating should maintain structural integrity during steps associatedwith preparation of the balloon catheter device include pleating,folding, and curing (such as heat treatment). In addition, it isdesirable for the coating to maintain structural integrity during theprocess of passing through the vasculature through a catheter and/orover the guide wire, with limited loss of the active agent. Yet, it isalso desirable upon inflation of the balloon at the desired site totransfer a substantial amount of the active agent from the balloon andonto the vessel wall. In addition, it is desirable to maximize uptake ofthe active agent into the tissue of the of the vessel wall and reducethe amount of active agent that is washed away into the blood flowingthrough the treatment site in the vasculature.

Embodiments herein can be useful to enhance one or more desirableproperties of drug delivery coatings, such as those properties desirablein the context of drug eluting balloon catheters, drug-containingballoon catheters and similar devices. In various embodiments, a drugdelivery device is provided that includes a substrate and coatedtherapeutic agent particles disposed on the substrate. The coatedtherapeutic agent particles can include a particulate hydrophobictherapeutic agent and a cationic agent disposed over the particulatehydrophobic therapeutic agent.

Referring now to FIG. 1 , a schematic cross-sectional diagram (not toscale) is provided of a coating in accordance with an embodiment herein.In this embodiment, coated therapeutic agent particles 104 are disposedon a substrate 102. Exemplary substrates are described in greater detailbelow. The coated therapeutic agent particles 104 can include aplurality of cationic agents 108 disposed over a particulate hydrophobictherapeutic agent 106. The coated therapeutic agent particles 104 can becontiguously coated with cationic agents 108. In other embodiments, thecationic agent 108 coating on the therapeutic agent particles 104 can bediscontinuous. Additionally, the particulate hydrophobic agents 106 cancoexist in a matrix with cationic agents 108 wherein the cationic agent108 does not coat the particulate hydrophobic agent 106. Variousmixtures of the embodiments described above can be found on a specificsubstrate 102. For example, but not limiting, a coating on a substratecan include coated therapeutic agent particles 104 contiguously coatedwith cationic agents 108 and particulate hydrophobic agents 106 in amatrix with cationic agents 108 wherein the cationic agent 108 does notcoat the particulate hydrophobic agent 106. It will be appreciated thatas actually applied there will be many hydrophobic therapeutic agentparticulates within a given coating and that a single particulate isshown in FIG. 1 just for purposes of ease of illustration. Exemplarycationic agents and hydrophobic therapeutic agents are described ingreater detail below. The charge provided by the cationic agents 108 canbe electrostatically attracted to negative charges and/or polar groupsassociated with the lipid bilayer 110 of a cell membrane and cellularcomponents within the lipid bilayer 110.

In some embodiments, nucleic acids may also be included in coatingsherein. By way of example, nucleic acids, including but not limited tosiRNA, may be associated with the cationic agent. Exemplary nucleicacids are described in greater detail below. Referring now to FIG. 2 , aschematic cross-sectional diagram (not to scale) is provided of anotherembodiment herein. In this embodiment, coated therapeutic agentparticles 204 are disposed on a substrate 202. The coated therapeuticagent particles 204 can include a plurality of cationic agents 208disposed over a particulate hydrophobic therapeutic agent 206. Nucleicacids 212 can be associated with the cationic agent. The charge providedby the cationic agents 208 can be electrostatically attracted tonegative charges and/or polar groups associated with the lipid bilayer210 of a cell membrane and cellular components within the lipid bilayer210.

In some embodiments, an additive may be included along with the coatedtherapeutic agent particles 304 in coatings herein. Referring now toFIG. 3 , a schematic cross-sectional diagram (not to scale) is providedof another embodiment. In this embodiment, coated therapeutic agentparticles 304 are disposed on a substrate 302. An additive 314 can bedisposed along with the coated therapeutic agent particles 304. Theamount of the additive 314 can be more than, less than, or equal to theamount of the coated therapeutic agent particles 304. In someembodiments, the additive 314 can form a matrix or layer in which thecoated therapeutic agent particles 304 are disposed. In variousembodiments, the additive can be hydrophilic. Exemplary additivecomponents are described in greater detail below. The coated therapeuticagent particles 304 can include a plurality of cationic agents 308disposed over a particulate hydrophobic therapeutic agent 306. Thecharge provided by the cationic agents 308 can be electrostaticallyattracted to negative charges and/or polar groups associated with thelipid bilayer 310 of a cell membrane and cellular components within thelipid bilayer 310.

In some embodiments, a hydrophilic polymer layer can be disposed on thesurface of the substrate, between the coated therapeutic agent particlesand the surface of the substrate. Exemplary polymers for the hydrophilicpolymer layer are described in greater detail below. Referring now toFIG. 4 , a schematic cross-sectional diagram (not to scale) is providedof another embodiment herein. In this embodiment, coated therapeuticagent particles 404 are disposed on a hydrophilic polymer layer 416,which is in turn disposed on a substrate 402. The coated therapeuticagent particles 404 can include a plurality of cationic agents 408disposed over a particulate hydrophobic therapeutic agent 406. Thecharge provided by the cationic agents 408 can be electrostaticallyattracted to negative charges and/or polar groups associated with thelipid bilayer 410 of a cell membrane and cellular components within thelipid bilayer 410.

Referring now to FIG. 5 , a schematic view of an exemplary device isshown in accordance with an embodiment. The device 500 can be, forexample, an angioplasty balloon catheter or a drug eluting ballooncatheter or a drug-containing balloon catheter. However, furtherexamples of exemplary devices are described in greater detail below. Thedevice 500 includes a catheter shaft 502 and a manifold end 505. Thedevice 500 also includes an inflatable balloon 504 disposed around thecatheter shaft 502. In FIG. 5 , the balloon 504 is shown in an inflatedconfiguration. The catheter shaft 502 can include a channel to conveyfluid through the catheter shaft 502 and to or from the balloon 504, sothat the balloon 504 can selectively go from a deflated configuration tothe inflated configuration and back again.

The manufacture of expandable balloons is well known in the art, and anysuitable process can be carried out to provide the expandable substrateportion of the insertable medical device as described herein. Catheterballoon construction is described in various references, for example,U.S. Pat. Nos. 4,490,421, 5,556,383, 6,210,364, 6,168,748, 6,328,710,and 6,482,348. Molding processes are typically performed for balloonconstruction. In an exemplary molding process, an extruded polymerictube is radially and axially expanded at elevated temperatures within amold having the desired shape of the balloon. The balloon can besubjected to additional treatments following the molding process. Forexample, the formed balloon can be subjected to additional heating stepsto reduce shrinkage of the balloon.

Referring back to FIG. 5 , the insertable medical device 500 can alsohave one or more non-expandable (or inelastic) portions. For example, ina balloon catheter, the catheter shaft 502 portion can be thenon-expandable portion. The non-expandable portion can be partially orentirely fabricated from a polymer. Polymers include those formed ofsynthetic polymers, including oligomers, homopolymers, and copolymersresulting from either addition or condensation polymerizations. Examplesof suitable addition polymers include, but are not limited to, acrylicssuch as those polymerized from methyl acrylate, methyl methacrylate,hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylic acid,methacrylic acid, glyceryl acrylate, glyceryl methacrylate,methacrylamide, and acrylamide; vinyls such as ethylene, propylene,vinyl chloride, vinyl acetate, vinyl pyrrolidone, vinylidene difluoride,and styrene. Examples of condensation polymers include, but are notlimited to, polyamides such as polycaprolactam, polylauryl lactam,polyhexamethylene adipamide, and polyhexamethylene dodecanediamide, andalso polyurethanes, polycarbonates, polyamides, polysulfones,poly(ethylene terephthalate), polydimethylsiloxanes, andpolyetherketone. The non-expandable portion can also be partially orentirely fabricated from a metal.

Referring now to FIG. 6 , a schematic cross-sectional diagram (not toscale) is provided of a drug delivery coating in accordance with variousembodiments herein. In this embodiment, particulate hydrophobictherapeutic agents 606 are disposed on a substrate 602. Exemplarysubstrates are described in greater detail below. A plurality ofcationic agents 608 are also disposed on the substrate. The particulatehydrophobic therapeutic agents 606 and the cationic agents 608 can forma matrix. It will be appreciated that as actually applied there can bemany more hydrophobic therapeutic agent particulates within a givenmatrix. Exemplary cationic agents and hydrophobic therapeutic agents aredescribed in greater detail below. The charge provided by the cationicagents 608 can be electrostatically attracted to negative charges and/orpolar groups associated with the lipid bilayer 610 of a cell membraneand cellular components within the lipid bilayer 610.

Referring now to FIG. 7 , a schematic cross-sectional diagram (not toscale) is provided of a drug delivery coating in accordance with variousembodiments herein. In this embodiment, particulate hydrophobictherapeutic agents 706 are disposed on a substrate 702. A plurality ofcationic agents 708 are also disposed on the substrate. The particulatehydrophobic therapeutic agents 706 and the cationic agents 708 can forma matrix. The particulate hydrophobic therapeutic agents 706 and thecationic agents 708 can be associated with one another and in some casescan form coated therapeutic agent particles 704 disposed on thesubstrate 702. The coated therapeutic agent particles 704 can include aplurality of cationic agents 708 disposed over a particulate hydrophobictherapeutic agent 706. It will be appreciated that as actually appliedthere can be many hydrophobic therapeutic agent particulates within agiven coating and that particulates shown in FIG. 7 are just forpurposes of ease of illustration. The charge provided by the cationicagents 708 can be electrostatically attracted to negative charges and/orpolar groups associated with the lipid bilayer 710 of a cell membraneand cellular components within the lipid bilayer 710.

In some embodiments, a hydrophilic polymer layer can be disposed on thesurface of the substrate, between the therapeutic agent, cationic agent,and/or coated therapeutic agent particles and the surface of thesubstrate. Exemplary polymers for the hydrophilic polymer layer aredescribed in greater detail below. Referring now to FIG. 8 , a schematiccross-sectional diagram (not to scale) is provided of a drug deliverycoating in accordance with various embodiments herein. A hydrophilicpolymer layer 816 is disposed on a substrate 802. Particulatehydrophobic therapeutic agents 806 are disposed on the hydrophilicpolymer layer 816. A plurality of cationic agents 808 can also bedisposed on the hydrophilic polymer layer 816. The particulatehydrophobic therapeutic agents 806 and the cationic agents 808 can beassociated with one another. The particulate hydrophobic therapeuticagents 806 and the cationic agents 808 can form a matrix. The chargeprovided by the cationic agents 808 can be electrostatically attractedto negative charges and/or polar groups associated with the lipidbilayer 810 of a cell membrane and cellular components within the lipidbilayer 810.

Referring now to FIG. 9 , a schematic cross-sectional diagram (not toscale) is provided of a drug delivery coating in accordance with variousembodiments herein. A hydrophilic polymer layer 916 is disposed on asubstrate 902. Particulate hydrophobic therapeutic agents 906 can bedisposed on the hydrophilic polymer layer 916. A plurality of cationicagents 908 can also disposed on the hydrophilic polymer layer 916. Theparticulate hydrophobic therapeutic agents 906 and the cationic agents908 can form a matrix. The particulate hydrophobic therapeutic agents906 and the cationic agents 908 can be associated with one another andin some cases can form coated therapeutic agent particles 904 disposedon the hydrophilic polymer layer 916. The coated therapeutic agentparticles 904 can include a plurality of cationic agents 908 disposedover a particulate hydrophobic therapeutic agent 906. The chargeprovided by the cationic agents 908 can be electrostatically attractedto negative charges and/or polar groups associated with the lipidbilayer 910 of a cell membrane and cellular components within the lipidbilayer 910.

Cationic Agents

Cationic agents used in embodiments herein can include compoundscontaining a portion having a positive charge in aqueous solution atneutral pH along with a portion that can exhibit affinity forhydrophobic surfaces (such as hydrophobic or amphiphilic properties) andcan therefore interface with hydrophobic active agents. In someembodiments, cationic agents used in embodiments herein can includethose having the general formula X—Y, wherein X is a radical including apositively charged group in aqueous solution at neutral pH and Y is aradical exhibiting hydrophobic properties. In some embodiments, thecationic agent can include a hydrophilic head and a hydrophobic tail,along with one or more positively charged groups, typically in the areaof the hydrophilic head.

Cationic agents of the present disclosure can include salts of cationicagents at various pH ranges, such as, but not limited to, halide salts,sulfate salts, carbonate salts, nitrate salts, phosphate salts, acetatesalts and mixtures thereof.

Cationic agents can specifically include cationic lipids and net neutrallipids that have a cationic group (neutral lipids with cationic groups).Exemplary lipids can include, but are not limited to,38-[N—(N,N′-dimethylaminoethane)-carbamoyl]cholesterol hydrochloride(DC-cholesterol); 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP);dimethyldioctadecylammonium (DDAB);1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EPC);1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA);1,2-di-(9Z-octadecenoyl)-3-dimethylammonium-propane (DODAP);1,2-dilinoleyloxy-3-dimethylaminopropane (DLinDMA) and derivativesthereof. Additional lipids can include, but are not limited to,1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE); cholesterol;1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC);1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE). Other cationicagents can include mono- or polyaminoalkanes such as spermine andspermidine.

Cationic agents can specifically include cationic polymers. Cationicagents can also include polycation-containing cyclodextrin (for example,but not limited to, amino cyclodextrin and derivatives thereof), aminodextran, histones, protamines, cationized human serum albumin,aminopolysaccharides such as chitosan, peptides such as poly-L-lysine,poly-L-ornithine, and poly(4-hydroxy-L-proline ester, and polyaminessuch as polyethylenimine (PEI; available from Sigma Aldrich),polyallylamine, polypropylenimine, polyamidoamine dendrimers (PAMAM;available from Sigma Aldrich), cationic polyoxazoline andpoly(beta-aminoesters). Cationic agents can also specifically includecationic lipidoids (as described by K. T. Love in the publication PNAS107, 1864-1869 (2010)). Other exemplary cationic polymers include, butare not limited to, block copolymers such as PEG-PEI and PLGA-PEIcopolymers. Other exemplary cationic agents include positively chargedgelatin (for example, base-treated gelatin), and the family of aminatedcucurbit[n]urils (wherein n=5, 6, 7, 8, 10).

In other embodiments of the present disclosure, cationic agentscontaining a portion having a positive charge in aqueous solutions atneutral pH include the following Compounds (A-I):

Additionally, other cationic agents include structures of the generalFormula I:

TABLE 1 Values for Variables x + z, y and R for Compounds J-R of FormulaI. Compound x + z y R Compound J 6 12.5 C₁₂H₂₅ Compound K 1.2 2 C₁₂H₂₅Compound L 6 39 C₁₂H₂₅ Compound M 6 12.5 C₁₄H₂₉ Compound N 1.2 2 C₁₄H₂₉Compound O 6 39 C₁₄H₂₉ Compound P 6 12.5 C₁₆H₃₃ Compound Q 1.2 2 C₁₆H₃₃Compound R 6 39 C₁₆H₃₃

Cationic agents, such as those listed above, can generally be preparedby the reaction of an appropriate hydrophobic epoxide (e.g. oleylepoxide) with a multi-functional amine (e.g. propylene diamine). Detailsof the synthesis of related cationic agents are described by K. T. Lovein the publication PNAS 107, 1864-1869 (2010) and Ghonaim et al., PharmaRes 27, 17-29 (2010).

It will be appreciated that polyamide derivatives of PEI (PEI-amides)can also be applied as cationic agents. PEI-amides can generally beprepared by reacting PEI with an acid or acid derivative such as an acidchloride or an ester to form various PEI-amides. For example, PEI can bereacted with methyl oleate to form PEI-amides.

In yet other embodiments cationic agents can include moieties used tocondense nucleic acids (for example lipids, peptides and other cationicpolymers). In some instances these cationic agents can be used to formlipoplexes and polyplexes.

Exemplary embodiments of cationic agents can also include, but are notlimited to, cationic agent derivatives that are photo reactive. Photoreactive groups are described below. Such cationic agent derivativesinclude PEI polymer derivatives of benzophenone and PAMAM polymerderivatives of benzophenone.

In some embodiments, the molecular weight of the cationic agent can beabout 1.2 kDa, 2.5 kDa, 10 kDa, 25 kDa, 250 kDa or even, in some cases,750 kDa. In yet other embodiments the molecular weight of the cationicagent can be in the range of 50-100 kDa, 70-100 kDa, 50-250 kDa, 25-100kDa, 2.5-750 kDa or even, in some cases, 2.5-2,000 kDa. Otherembodiments include molecular weights greater than 1.2 kDa, 2.5 kDa, 10kDa, 25 kDa, 250 kDa or even, in some cases, greater than 750 kDa. Otherembodiments can include cationic agents up to 2,000 kDa.

Low molecular weight cationic agent monomers or low molecular weightcationic oligomers can be combined with hydrophobic active agent toproduce a reactive coating. These reactive coatings can then be coatedonto a substrate and thermally polymerized or polymerized withUV-radiation. Exemplary monomers include, but are not limited to,aziridine, vinylamine, allylamine and oligomers from 80 g/mol to 1200g/mol. Crosslinkers (e.g., 1,2-dichloroethane, epichlorohydrin,1,6-diisocyanatohexane) could be used to crosslink oligomers.

Additive Components

In some embodiments of the present disclosure the additive componentscan be hydrophilic in nature. Exemplary hydrophilic polymers include,but are not limited to, PEG, PVP and PVA.

Exemplary additive components can include saccharides. Saccharides caninclude monosaccharides, disaccharides, trisaccharides,oligosaccharides, and polysaccharides. Polysaccharides can be linear orbranched polysaccharides. Exemplary saccharides can include but are notlimited to dextrose, sucrose, maltose, mannose, trehalose, and the like.Exemplary saccharides can further include, but are not limited to,polysaccharides including pentose, and/or hexose subunits, specificallyincluding glucans such as glycogen and amylopectin, and dextrinsincluding maltodextrins, fructose, mannose, galactose, and the like.Polysaccharides can also include gums such as pullulan, arabinose,galactan, etc.

Saccharides can also include derivatives of polysaccharides. It will beappreciated that polysaccharides include a variety of functional groupsthat can serve as attachment points or can otherwise be chemicallymodified in order to alter characteristics of the saccharide. As justone example, it will be appreciated that saccharide backbones generallyinclude substantial numbers of hydroxyl groups that can be utilized toderivatize the saccharide.

Saccharides can also include copolymers and/or terpolymers, and thelike, that include saccharide and/or saccharide subunits and/or blocks.

Polysaccharides used with embodiments herein can have various molecularweights. By way of example, glycogen used with embodiments herein canhave a molecular weight of greater than about 250,000. In someembodiments glycogen used with embodiments herein can have a molecularweight of between about 100,000 and 10,000,000 Daltons.

Refinement of the molecular weight of polysaccharides can be carried outusing diafiltration. Diafiltration of polysaccharides such asmaltodextrin can be carried out using ultrafiltration membranes withdifferent pore sizes. As an example, use of one or more cassettes withmolecular weight cut-off membranes in the range of about 1K to about 500K can be used in a diafiltration process to provide polysaccharidepreparations with average molecular weights in the range of less than500 kDa, in the range of about 100 kDa to about 500 kDa, in the range ofabout 5 kDa to about 30 kDa, in the range of about 30 kDa to about 100kDa, in the range of about 10 kDa to about 30 kDa, or in the range ofabout 1 kDa to about 10 kDa.

It will be appreciated that polysaccharides such as maltodextrin andamylose of various molecular weights are commercially available from anumber of different sources. For example, Glucidex™ 6 (avg. molecularweight ˜95,000 Da) and Glucidex™ 2 (avg. molecular weight ˜300,000 Da)are available from Roquette (France); and MALTRIN™ maltodextrins ofvarious molecular weights, including molecular weights from about 12,000Da to 15,000 Da are available from GPC (Muscatine, Iowa). Examples ofother hydrophobic polysaccharide derivatives are disclosed in US PatentPublication 2007/0260054 (Chudzik), which is incorporated herein byreference.

Exemplary additive components can include amphiphilic compounds.Amphiphilic compounds include those having a relatively hydrophobicportion and a relatively hydrophilic portion. Exemplary amphiphiliccompounds can include, but are not limited to, polymers including, atleast blocks of, polyvinylpyrrolidone, polyvinyl alcohol, polyethyleneglycol, polyoxazolines (such as poly(2-alkyloxazoline) and derivatives)and the like. Exemplary amphiphilic compounds can specifically includepoloxamers. Poloxamers are nonionic triblock copolymers composed of acentral hydrophobic chain of polyoxypropylene flanked by two hydrophilicchains of polyoxyethylene. Poloxamers are frequently referred to by thetrade name PLURONIC®. It will be appreciated that many aspects of thecopolymer can be varied such the characteristics can be customized. Oneexemplary poloxamer is PLURONIC® F68 (non-ionic, co-polymer of ethyleneand propylene oxide commercially available from BASF Corporation; alsodesignated as F68 and poloxamer F68), which refers to a poloxamer havinga solid form at room temperature, a polyoxypropylene molecular mass ofapproximately 1,800 g/mol and roughly 80% polyoxyethylene content, witha total molecular weight of approximately 8,400 g/mol, the copolymerterminating in primary hydroxyl groups.

Exemplary additive components can further include compounds thatstabilize poorly water soluble pharmaceutical agents. Exemplary additivecomponents providing such stabilization include biocompatible polymers,for example albumins. Additional additive components are described inU.S. Pat. No. 7,034,765 (De et al.), the disclosure of which isincorporated herein by reference. Stabilization of suspensions andemulsions can also be provided by compounds, for example, such assurfactants (e.g. F68).

Various additive components can be added as an optional topcoat over thelayer containing the hydrophobic active agent. In some embodiments, thetopcoat can be applied to modify the release characteristic of thehydrophobic active agent. Other topcoats can be added as a protectionlayer to reduce inadvertent loss of the hydrophobic active agent throughfriction or general wear. For example, the topcoat can act as aprotection layer for handling purposes during packaging or to protectthe hydrophobic active agent until the hydrophobic active can bedelivered to the target site in the body, or both. For example, theoptional topcoat can include polyvinylpyrrolidone (PVP), polyacrylicacid (PAA), and polyurethane.

Hydrophobic Active Agents

It will be appreciated that hydrophobic active agents of embodimentsherein (e.g., particulate hydrophobic therapeutic agents), can includeagents having many different types of activities. The terms “activeagent” and “therapeutic agent” as used herein shall be coterminousunless the context dictates otherwise. Hydrophobic active agents canspecifically include those having solubility in water of less than about100 μg/mL at 25 degrees Celsius and neutral pH. In various embodiments,hydrophobic active agents can specifically include those havingsolubility in water of less than about 10 μg/mL at 25 degrees Celsiusand neutral pH. In some embodiments, hydrophobic active agents canspecifically include those having solubility in water of less than about5 μg/ml at 25 degrees Celsius and neutral pH.

In some exemplary embodiments, active agents can include, but are notlimited to, antiproliferatives such as paclitaxel, sirolimus(rapamycin), zotarolimus, everolimus, temsirolimus, pimecrolimus,tacrolimus, and ridaforolimus; analgesics and anti-inflammatory agentssuch as aloxiprin, auranofin, azapropazone, benorylate, diflunisal,etodolac, fenbufen, fenoprofen calcim, flurbiprofen, ibuprofen,indomethacin, ketoprofen, meclofenamic acid, mefenamic acid, nabumetone,naproxen, oxyphenbutazone, phenylbutazone, piroxicam, sulindac;anti-arrhythmic agents such as amiodarone HCl, disopyramide, flecainideacetate, quinidine sulphate; anti-bacterial agents such as benethaminepenicillin, cinoxacin, ciprofloxacin HCl, clarithromycin, clofazimine,cloxacillin, demeclocycline, doxycycline, erythromycin, ethionamide,imipenem, nalidixic acid, nitrofurantoin, rifampicin, spiramycin,sulphabenzamide, sulphadoxine, sulphamerazine, sulphacetamide,sulphadiazine, sulphafurazole, sulphamethoxazole, sulphapyridine,tetracycline, trimethoprim; anti-coagulants such as dicoumarol,dipyridamole, nicoumalone, phenindione; anti-hypertensive agents such asamlodipine, benidipine, darodipine, dilitazem HCl, diazoxide,felodipine, guanabenz acetate, isradipine, minoxidil, nicardipine HCl,nifedipine, nimodipine, phenoxybenzamine HCl, prazosin HCL, reserpine,terazosin HCL; anti-muscarinic agents: atropine, benzhexol HCl,biperiden, ethopropazine HCl, hyoscyamine, mepenzolate bromide,oxyphencylcimine HCl, tropicamide; anti-neoplastic agents andimmunosuppressants such as aminoglutethimide, amsacrine, azathioprine,busulphan, chlorambucil, cyclosporin, dacarbazine, estramustine,etoposide, lomustine, melphalan, mercaptopurine, methotrexate,mitomycin, mitotane, mitozantrone, procarbazine HCl, tamoxifen citrate,testolactone; beta-blockers such as acebutolol, alprenolol, atenolol,labetalol, metoprolol, nadolol, oxprenolol, pindolol, propranolol;cardiac inotropic agents such as amrinone, digitoxin, digoxin,enoximone, lanatoside C, medigoxin; corticosteroids such asbeclomethasone, betamethasone, budesonide, cortisone acetate,desoxymethasone, dexamethasone, fludrocortisone acetate, flunisolide,flucortolone, fluticasone propionate, hydrocortisone,methylprednisolone, prednisolone, prednisone, triamcinolone; lipidregulating agents such as bezafibrate, clofibrate, fenofibrate,gemfibrozil, probucol; nitrates and other anti-anginal agents such asamyl nitrate, glyceryl trinitrate, isosorbide dinitrate, isosorbidemononitrate, pentaerythritol tetranitrate.

Other exemplary embodiments of active agents include, but are notlimited to, active agents for treatment of hypertension (HTN), such asguanethidine.

In a particular embodiment, the hydrophobic active agents are selectedfrom the group consisting of paclitaxel, sirolimus (rapamycin) andmixtures thereof.

In some embodiments, a hydrophobic active agents can be conjugated to acationic agent. The conjugation can include a hydrophobic active agentcovalently bonded to the cationic agent. In some embodiments wherein thehydrophobic agent is conjugated to the cationic agent a linking agentcan be used to attach the hydrophobic agent to the cationic agent.Suitable linking agents include, but are not limited to, polyethyleneglycol, polyethylene oxide and polypeptides of naturally-occurring andnon-naturally occurring amino acids. In some embodiments, linking agentscan be biodegradable or cleavable in vivo to assist in release of thehydrophobic active agents. Exemplary linking agents can further includealkane or aromatic compounds with heteroatom-substitutions such as N, S,Si, Se or O.

Particle size and size distribution of a particulate preparation can bedetermined using any one of various techniques known in the art. In onemode of practice, laser diffraction can be used to measure particle sizeand distribution. In laser diffraction a laser beam passes through adispersed particulate sample and angular variation in intensity of lightscattered is measured. The angle of light scattering is greater forlarge particles and less for smaller particles, and the angularscattering intensity data can be collected and analyzed to generate aparticle size profile.

Analysis of particulate size and distribution can be performed usinglaser light scattering equipment such as Malvern System 4700, (forparticles from 1 nm to 3 μm) or Horiba LA-930 (e.g., for particles from100 nm to 2 mm). The output from such analyzers can provide informationon the sizes of individual particulates, and the overall amount ofparticulates of these sizes reflecting the distribution of particulatesin terms of size. Analysis providing data on the size distribution canbe provided in the form of a histogram, graphically representing thesize and size distribution of all the particulates in a preparation.

Exemplary particulate hydrophobic therapeutic agents can have differentmorphological characteristics. In some embodiments the particulatehydrophobic therapeutic agent can be crystalline. In yet otherembodiments of the present disclosure the particulate hydrophobictherapeutic agent can be amorphous. Additionally, combinations ofcrystalline and amorphous particulate hydrophobic therapeutic agents canbe desirable in order to achieve, for example, desired solubilities ofthe particulate hydrophobic therapeutic agents.

In some embodiments, the particulate hydrophobic therapeutic agent canhave an average diameter (“dn”, number average) that is less than about30 μm or less than about 10 μm. Also, in some embodiments, theparticulate hydrophobic therapeutic agent can have an average diameterof about 100 nm or larger. For example, the microparticulates associatedwith the expandable elastic portion can have an average diameter in therange of about 100 nm to about 10 μm, about 150 nm to about 2 μm, about200 nm to about 5 μm, or even about 0.3 μm to about 1 μm.

Nucleic Acids

Nucleic acids used with embodiments of the invention can include varioustypes of nucleic acids that can function to provide a therapeuticeffect. Exemplary types of nucleic acids can include, but are notlimited to, ribonucleic acids (RNA), deoxyribonucleic acids (DNA), smallinterfering RNA (siRNA), micro RNA (miRNA), piwi-interacting RNA(piRNA), short hairpin RNA (shRNA), antisense nucleic acids, aptamers,ribozymes, locked nucleic acids and catalytic DNA. In a particularembodiment, the nucleic acid used is siRNA and/or derivatives thereof.

In some exemplary embodiments of the present disclosure, the range ofthe percent ratio of hydrophobic active agent to cationic agent (e.g. %PTX/% PEI or % PTX/% DOTAP; wt/wt) is from about 99.9/0.1 to about70/30. In yet other embodiments it can be appreciated that the range ofthe percent ratio of hydrophobic active agents is from about 99/1 toabout 73/27; from about 98/2 to about 75/25; from about 98/2 to about86/14; from about 97/3 to about 88/12; from about 95/5 to about 90/10;and even in some exemplary embodiments from about 93/7 to about 91/9.

Hydrophilic Base Coatings

One class of hydrophilic polymers useful as polymeric materials forhydrophilic base coat formation is synthetic hydrophilic polymers.Synthetic hydrophilic polymers that are biostable (i.e., that show noappreciable degradation in vivo) can be prepared from any suitablemonomer including acrylic monomers, vinyl monomers, ether monomers, orcombinations of any one or more of these types of monomers. Acrylicmonomers include, for example, methacrylate, methyl methacrylate,hydroxyethyl methacrylate, hydroxyethyl acrylate, methacrylic acid,acrylic acid, glycerol acrylate, glycerol methacrylate, acrylamide,methacrylamide, dimethylacrylamide (DMA), and derivatives and/ormixtures of any of these. Vinyl monomers include, for example, vinylacetate, vinylpyrrolidone, vinyl alcohol, and derivatives of any ofthese. Ether monomers include, for example, ethylene oxide, propyleneoxide, butylene oxide, and derivatives of any of these. Examples ofpolymers that can be formed from these monomers includepoly(acrylamide), poly(methacrylamide), poly(vinylpyrrolidone),poly(acrylic acid), poly(ethylene glycol), poly(vinyl alcohol), andpoly(HEMA). Examples of hydrophilic copolymers include, for example,methyl vinyl ether/maleic anhydride copolymers and vinylpyrrolidone/(meth)acrylamide copolymers. Mixtures of homopolymers and/orcopolymers can be used.

Examples of some acrylamide-based polymers, such aspoly(N,Ndimethylacrylamide-co-aminopropylmethacrylamide) andpoly(acrylamide-co-N,Ndimethylaminopropylmethacrylamide) are describedin example 2 of U.S. Pat. No. 7,807,750 (Taton et al.), the disclosureof which is incorporated herein by reference.

Other hydrophilic polymers that can be useful in the present disclosureare derivatives of acrylamide polymers with photoreactive groups. Onesuch representative hydrophilic polymer can be the copolymerization ofN-[3-(4-benzoylbenzamido)propyl]methacrylamide (Formula I) withN-(3-aminopropyl)methacrylamide (Formula H) to produce the polymerpoly(N-3-aminopropyl)methacrylamide-co-N-[3-(4-benzoylbenzamido)propyl]methacrylamide(Formula HI). The preparation of the polymer is disclosed in Example 1of US Patent Publication 2007/0032882 (to Lodhi, et al.), the fullcontent of which is incorporated herein by reference.

In some embodiments, the hydrophilic polymer can be a vinyl pyrrolidonepolymer, or a vinyl pyrrolidone/(meth)acrylamide copolymer such aspoly(vinylpyrrolidone-co-methacrylamide). If a PVP copolymer is used, itcan be a copolymer of vinylpyrrolidone and a monomer selected from thegroup of acrylamide monomers. Exemplary acrylamide monomers include(meth)acrylamide and (meth)acrylamide derivatives, such asalkyl(meth)acrylamide, as exemplified by dimethylacrylamide, andaminoalkyl(meth)acrylamide, as exemplified by aminopropylmethacrylamideand dimethylaminopropylmethacrylamide. For example,poly(vinylpyrrolidone-co-N,N dimethylaminopropylmethacrylamide) isdescribed in example 2 of U.S. Pat. No. 7,807,750 (Taton et al.).

In one embodiment, the polymers and copolymers as described arederivatized with one or more photoactivatable group(s). Exemplaryphotoreactive groups that can be pendent from biostable hydrophilicpolymer include aryl ketones, such as acetophenone, benzophenone,anthraquinone, anthrone, quinone, and anthrone-like heterocycles. Arylketones herein can specifically include diaryl ketones. Polymers hereincan provide a hydrophilic polymer having a pendent activatablephotogroup that can be applied to the expandable and collapsiblestructure, and can then treated with actinic radiation sufficient toactivate the photogroups and cause covalent bonding to a target, such asthe material of the expandable and collapsible structure. Use ofphoto-hydrophilic polymers can be used to provide a durable coating of aflexible hydrogel matrix, with the hydrophilic polymeric materialscovalently bonded to the material of the expandable and collapsiblestructure.

A hydrophilic polymer having pendent photoreactive groups can be used toprepare the flexible hydrogel coating. Methods of preparing hydrophilicpolymers having photoreactive groups are known in the art. For example,methods for the preparation of photo-PVP are described in U.S. Pat. No.5,414,075, the disclosure of which is incorporated herein by reference.Hydrophilic photo-polyacrylamide polymers such aspoly(acrylamide-co-N-(3-(4-benzoylbenzamido)propyl)methacylamide),“Photo-PAA”, and derivatives thereof can be used to form hydrophilicbase coats in exemplary embodiments of the present disclosure. Methodsfor the preparation of photo-polyacrylamide are described in U.S. Pat.No. 6,007,833, the disclosure of which is incorporated herein byreference.

Other embodiments of hydrophilic base coats include derivatives ofphoto-polyacrylamide polymers incorporating additional reactivemoieties. Some exemplary reactive moieties include N-oxysuccinimide andglycidyl methacrylate. Representative photo-polyacrylamide derivativesincorporating additional reactive moieties includepoly(acrylamide-co-maleic-6-aminocaproicacid-N-oxysuccinimide-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamide)andpoly(acrylamide-co-(3-(4-benzoylbenzamido)propyl)methacrylamide)-co-glycidylmethacrylate.Additional photo-polyacrylamide polymers incorporating reactive moietiesare described in U.S. Pat. No. 6,465,178 (to Chappa, et al.), U.S. Pat.No. 6,762,019 (to Swan, et al.) and U.S. Pat. No. 7,309,593 (to Ofstead,et al.), the disclosures of which are herein incorporated by reference.

Other embodiments of exemplary hydrophilic base coats that includederivatives of photo-polyacrylamide polymers incorporating additionalreactive moieties can be found in U.S. Pat. No. 6,514,734 (to Clapper,et al.), the disclosure of which is incorporated herein by reference inits entirety.

In yet other embodiments, the hydrophilic base coat can includederivatives of photo-polyacrylamide polymers incorporating chargedmoieties. Charged moieties include both positively and negativelycharged species. Exemplary charged species include, but are not limitedto, sulfonates, phosphates and quaternary amine derivatives. Someexamples include the negatively charged species N-acetylatedpoly(acrylamide-co-sodium-2-acrylamido-2-methylpropanesulfonate-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamide)-co-methoxypoly(ethylene glycol) monomethacrylate. Other negatively charged speciesthat can be incorporated into the hydrophilic base coat are described inU.S. Pat. No. 4,973,993, the disclosure of which is incorporated hereinby reference in its entirety. Positively charged species can includepoly(acrylamide-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamide)-co-(3-(methacryloylamino)propyl)trimethylammoniumchloride. Other positively charged species that can be incorporated intothe hydrophilic base coat are described in U.S. Pat. No. 5,858,653 (toDuran et al.), the disclosure of which is incorporated herein byreference in its entirety.

In another embodiment, the polymers and copolymers as described arederivatized with one or more polymerizable group(s). Polymers withpendent polymerizable groups are commonly referred to as macromers. Thepolymerizable group(s) can be present at the terminal portions (ends) ofthe polymeric strand or can be present along the length of the polymer.In one embodiment polymerizable groups are located randomly along thelength of the polymer.

Exemplary hydrophilic polymer coatings can be prepared using polymergrafting techniques. Polymer grafting techniques can include applying anonpolymeric grafting agent and monomers to a substrate surface thencausing polymerization of the monomers on the substrate surface uponappropriate activation (for example, but not limited to, UV radiation)of the grafting agent. Grafting methods producing hydrophilic polymericsurfaces are exemplified in U.S. Pat. Nos. 7,348,055; 7,736,689 and8,039,524 (all to Chappa et al.) the full disclosures of which areincorporated herein by reference.

Optionally, the coating can include a crosslinking agent. A crosslinkingagent can promote the association of polymers in the coating, or thebonding of polymers to the coated surface. The choice of a particularcrosslinking agent can depend on the ingredients of the coatingcomposition.

Suitable crosslinking agents can include two or more activatable groups,which can react with the polymers in the composition. Suitableactivatable groups can include photoreactive groups as described herein,like aryl ketones, such as acetophenone, benzophenone, anthraquinone,anthrone, quinone, and anthrone-like heterocycles. A crosslinking agentincluding a photoreactive group can be referred to as aphoto-crosslinker or photoactivatable crosslinking agent. Thephotoactivatable crosslinking agent can be ionic, and can have goodsolubility in an aqueous composition. Thus, in some embodiments, atleast one ionic photoactivatable crosslinking agent can be used to formthe coating. The ionic crosslinking agent can include an acidic group orsalt thereof, such as selected from sulfonic acids, carboxylic acids,phosphonic acids, salts thereof, and the like. Exemplary counter ionsinclude alkali, alkaline earths metals, ammonium, protonated amines, andthe like.

Exemplary ionic photoactivatable crosslinking agents include4,5-bis(4-benzoylphenylmethyleneoxy) benzene-1,3-disulfonic acid orsalt; 2,5-bis(4-benzoylphenylmethyleneoxy)benzene-1,4-disulfonic acid orsalt; 2,5-bis(4-benzoylmethyleneoxy)benzene-1-sulfonic acid or salt;N,N-bis[2-(4-benzoylbenzyloxy)ethyl]-2-aminoethanesulfonic acid or salt,and the like. See U.S. Pat. No. 6,077,698 (Swan et al.), U.S. Pat. No.6,278,018 (Swan), U.S. Pat. No. 6,603,040 (Swan) and U.S. Pat. No.7,138,541 (Swan) the disclosures of which are incorporated herein byreference.

Other exemplary ionic photoactivatable crosslinking agents includeethylenebis(4-benzoylbenzyldimethylammonium) dibromide andhexamethylenebis(4-benzoylbenzyldimethylammonium) dibromide and thelike. See U.S. Pat. No. 5,714,360 (Swan et al.) the disclosures of whichare incorporated herein by reference.

In yet other embodiments, restrained multifunctional reagents withphotoactivable crosslinking groups can be used. In some examples theserestrained multifunctional reagents include tetrakis (4-benzoylbenzylether) of pentaerthyritol and the tetrakis (4-benzoylbenzoate ester) ofpentaerthyritol. See U.S. Pat. No. 5,414,075 (Swan et al.) and U.S. Pat.No. 5,637,460 (Swan et al.) the disclosures of which are incorporatedherein by reference.

Additional crosslinking agents can include those having formulaPhoto¹-LG-Photo², wherein Photo¹ and Photo² independently represent atleast one photoreactive group and LG represents a linking groupcomprising at least one silicon or at least one phosphorus atom, whereinthe degradable linking agent comprises a covalent linkage between atleast one photoreactive group and the linking group, wherein thecovalent linkage between at least one photoreactive group and thelinking group is interrupted by at least one heteroatom. See U.S. Pat.No. 8,889,760 (Kurdyumov, et al.), the disclosure of which isincorporated herein by reference. Further crosslinking agents caninclude those having a core molecule with one or more charged groups andone or more photoreactive groups covalently attached to the coremolecule by one or more degradable linkers. See U.S. Publ. Pat. App. No.2011/0144373 (Swan, et al.), the disclosure of which is incorporatedherein by reference.

Crosslinking agents used in accordance with embodiments herein caninclude those with at least two photoreactive groups. Exemplarycrosslinking agents are described in U.S. Pat. No. 8,889,760, thecontent of which is herein incorporated by reference in its entirety.

In some embodiments, the first and/or second crosslinking agent can havea molecular weight of less than about 1500 kDa. In some embodiments thecrosslinking agent can have a molecular weight of less than about 1200,1100, 1000, 900, 800, 700, 600, 500, or 400.

In some embodiments, at least one of the first and second crosslinkingagents comprising a linking agent having formula Photo¹-LG-Photo²,wherein Photo¹ and Photo², independently represent at least onephotoreactive group and LG represents a linking group comprising atleast one silicon or at least one phosphorus atom, there is a covalentlinkage between at least one photoreactive group and the linking group,wherein the covalent linkage between at least one photoreactive groupand the linking group is interrupted by at least one heteroatom.

In some embodiments, at least one of the first and second crosslinkingagents comprising a linking agent having a formula selected from:

wherein R1, R2, R8 and R9 are any substitution; R3, R4, R6 and R7 arealkyl, aryl, or a combination thereof; R5 is any substitution; and eachX, independently, is O, N, Se, S, or alkyl, or a combination thereof,

-   -   wherein R1 and R5 are any substitution; R2 and R4 can be any        substitution, except OH; R3 can be alkyl, aryl, or a combination        thereof; and X, independently, are O, N, Se, S, alkylene, or a        combination thereof;

-   -   wherein R1, R2, R4 and R5 are any substitution; R3 is any        substitution; R6 and R7 are alkyl, aryl, or a combination        thereof; and each X can independently be O, N, Se, S, alkylene,        or a combination thereof; and

In a particular embodiment, the crosslinking agent can bebis(4-benzoylphenyl) phosphate.

In some embodiments, the photoactivatable crosslinking agent can beionic, and can have good solubility in an aqueous composition, such asthe first and/or second coating composition. Thus, in some embodiments,at least one ionic photoactivatable crosslinking agent is used to formthe coating. In some cases, an ionic photoactivatable crosslinking agentcan crosslink the polymers within the second coating layer which canalso improve the durability of the coating.

Any suitable ionic photoactivatable crosslinking agent can be used. Insome embodiments, the ionic photoactivatable crosslinking agent is acompound of formula I: X₁—Y—X₂ where Y is a radical containing at leastone acidic group, basic group, or a salt of an acidic group or basicgroup. X₁ and X₂ are each independently a radical containing a latentphotoreactive group. The photoreactive groups can be the same as thosedescribed herein. Spacers can also be part of X₁ or X₂ along with thelatent photoreactive group. In some embodiments, the latentphotoreactive group includes an aryl ketone or a quinone.

The radical Y in formula I provides the desired water solubility for theionic photoactivatable crosslinking agent. The water solubility (at roomtemperature and optimal pH) is at least about 0.05 mg/ml. In someembodiments, the solubility is about 0.1 to about 10 mg/ml or about 1 toabout 5 mg/ml.

In some embodiments of formula I, Y is a radical containing at least oneacidic group or salt thereof. Such a photoactivatable crosslinking agentcan be anionic depending upon the pH of the coating composition.Suitable acidic groups include, for example, sulfonic acids, carboxylicacids, phosphonic acids, and the like. Suitable salts of such groupsinclude, for example, sulfonate, carboxylate, and phosphate salts. Insome embodiments, the ionic crosslinking agent includes a sulfonic acidor sulfonate group. Suitable counter ions include alkali, alkalineearths metals, ammonium, protonated amines, and the like.

For example, a compound of formula I can have a radical Y that containsa sulfonic acid or sulfonate group; X₁ and X₂ can contain photoreactivegroups such as aryl ketones. Such compounds include4,5-bis(4-benzoylphenylmethyleneoxy)benzene-1,3-disulfonic acid or salt;2,5-bis(4-benzoylphenylmethyleneoxy)benzene-1,4-disulfonic acid or salt;2,5-bis(4-benzoylmethyleneoxy)benzene-1-sulfonic acid or salt;N,N-bis[2-(4-benzoylbenzyloxy)ethyl]-2-aminoethanesulfonic acid or salt,and the like. See U.S. Pat. No. 6,278,018. The counter ion of the saltcan be, for example, ammonium or an alkali metal such as sodium,potassium, or lithium.

In other embodiments of formula I, Y can be a radical that contains abasic group or a salt thereof. Such Y radicals can include, for example,an ammonium, a phosphonium, or a sulfonium group. The group can beneutral or positively charged, depending upon the pH of the coatingcomposition. In some embodiments, the radical Y includes an ammoniumgroup. Suitable counter ions include, for example, carboxylates,halides, sulfate, and phosphate. For example, compounds of formula I canhave a Y radical that contains an ammonium group; X₁ and X₂ can containphotoreactive groups that include aryl ketones. Such photoactivatablecrosslinking agents include ethylenebis(4-benzoylbenzyldimethylammonium)salt; hexamethylenebis (4-benzoylbenzyldimethylammonium) salt;1,4-bis(4-benzoylbenzyl)-1,4-dimethylpiperazinediium) salt,bis(4-benzoylbenzyl)hexamethylenetetraminediium salt,bis[2-(4-benzoylbenzyldimethylammonio)ethyl]-4-benzoylbenzylmethylammoniumsalt, 4,4-bis(4-benzoylbenzyl)morpholinium salt;ethylenebis[(2-(4-benzoylbenzyldimethylammonio)ethyl)-4-benzoylbenzylmethylammonium]salt; and 1,1,4,4-tetrakis(4-benzoylbenzyl)piperzinediium salt. See U.S.Pat. No. 5,714,360. The counter ion is typically a carboxylate ion or ahalide. On one embodiment, the halide is bromide.

In other embodiments, the ionic photoactivatable crosslinking agent canbe a compound having the formula:

wherein X¹ includes a first photoreactive group; X² includes a secondphotoreactive group; Y includes a core molecule; Z includes at least onecharged group; D¹ includes a first degradable linker; and D² includes asecond degradable linker. Additional exemplary degradable ionicphotoactivatable crosslinking agents are described in US PatentApplication Publication US 2011/0144373 (Swan et al., “Water SolubleDegradable Crosslinker”), the disclosure of which is incorporated hereinby reference.

In some aspects a non-ionic photoactivatable crosslinking agent can beused. In one embodiment, the non-ionic photoactivatable crosslinkingagent has the formula XR₁R₂R₃R₄, where X is a chemical backbone, and R₁,R₂, R₃, and R₄ are radicals that include a latent photoreactive group.Exemplary non-ionic crosslinking agents are described, for example, inU.S. Pat. Nos. 5,414,075 and 5,637,460 (Swan et al., “RestrainedMultifunctional Reagent for Surface Modification”). Chemically, thefirst and second photoreactive groups, and respective spacers, can bethe same or different.

In other embodiments, the non-ionic photoactivatable crosslinking agentcan be represented by the formula:

PG²-LE²-X-LE¹-PG¹

-   -   wherein PG¹ and PG² include, independently, one or more        photoreactive groups, for example, an aryl ketone photoreactive        group, including, but not limited to, aryl ketones such as        acetophenone, benzophenone, anthraquinone, anthrone,        anthrone-like heterocycles, their substituted derivatives or a        combination thereof; LE¹ and LE² are, independently, linking        elements, including, for example, segments that include urea,        carbamate, or a combination thereof; and X represents a core        molecule, which can be either polymeric or non-polymeric,        including, but not limited to a hydrocarbon, including a        hydrocarbon that is linear, branched, cyclic, or a combination        thereof; aromatic, non-aromatic, or a combination thereof;        monocyclic, polycyclic, carbocyclic, heterocyclic, or a        combination thereof; benzene or a derivative thereof; or a        combination thereof. Other non-ionic crosslinking agents are        described, for example, in U.S. application Ser. No. 13/316,030        filed Dec. 9, 2011 (Publ. No. US 2012/0149934) (Kurdyumov,        “Photocrosslinker”), the disclosure of which is incorporated        herein by reference.

Further embodiments of non-ionic photoactivatable crosslinking agentscan include, for example, those described in US Pat. Publication2013/0143056 (Swan et al., “Photo-Vinyl Primers/Crosslinkers”), thedisclosure of which is incorporated herein by reference. Exemplarycrosslinking agents can include non-ionic photoactivatable crosslinkingagents having the general formula R¹—X—R², wherein R¹ is a radicalcomprising a vinyl group, X is a radical comprising from about one toabout twenty carbon atoms, and R² is a radical comprising aphotoreactive group.

A single photoactivatable crosslinking agent or any combination ofphotoactivatable crosslinking agents can be used in forming the coating.In some embodiments, at least one nonionic crosslinking agent such astetrakis(4-benzoylbenzyl ether) of pentaerythritol can be used with atleast one ionic crosslinking agent. For example, at least one non-ionicphotoactivatable crosslinking agent can be used with at least onecationic photoactivatable crosslinking agent such as anethylenebis(4-benzoylbenzyldimethylammonium) salt or at least oneanionic photoactivatable crosslinking agent such as4,5-bis(4-benzoyl-phenylmethyleneoxy)benzene-1,3-disulfonic acid orsalt. In another example, at least one nonionic crosslinking agent canbe used with at least one cationic crosslinking agent and at least oneanionic crosslinking agent. In yet another example, a least one cationiccrosslinking agent can be used with at least one anionic crosslinkingagent but without a non-ionic crosslinking agent.

An exemplary crosslinking agent is disodium4,5-bis[(4-benzoylbenzyl)oxy]-1,3-benzenedisulfonate (DBDS). Thisreagent can be prepared by combining4,5-Dihydroxylbenzyl-1,3-disulfonate (CHBDS) with4-bromomethylbenzophenone (BMBP) in THF and sodium hydroxide, thenrefluxing and cooling the mixture followed by purification andrecrystallization (also as described in U.S. Pat. No. 5,714,360,incorporated herein by reference).

Further crosslinking agents can include the crosslinking agentsdescribed in U.S. Publ. Pat. App. No. 2010/0274012 (to Guire et al.) andU.S. Pat. No. 7,772,393 (to Guire et al.) the content of all of which isherein incorporated by reference.

In some embodiments, crosslinking agents can include boron-containinglinking agents including, but not limited to, the boron-containinglinking agents disclosed in US Pat. Publication 2013/0302529 entitled“Boron-Containing Linking Agents” by Kurdyumov et al., the content ofwhich is herein incorporated by reference. By way of example, linkingagents can include borate, borazine, or boronate groups and coatings anddevices that incorporate such linking agents, along with relatedmethods. In an embodiment, the linking agent includes a compound havingthe structure (I):

wherein R¹ is a radical comprising a photoreactive group; R² is selectedfrom OH and a radical comprising a photoreactive group, an alkyl groupand an aryl group; and R³ is selected from OH and a radical comprising aphotoreactive group. In some embodiments the bonds B—R¹, B—R² and B—R³can be chosen independently to be interrupted by a heteroatom, such asO, N, S, or mixtures thereof.

Additional agents for use with embodiments herein can includestilbene-based reactive compounds including, but not limited to, thosedisclosed in U.S. Pat. No. 8,487,137, entitled “Stilbene-Based ReactiveCompounds, Polymeric Matrices Formed Therefrom, and ArticlesVisualizable by Fluorescence” by Kurdyumov et al., the content of whichis herein incorporated by reference.

Additional photoreactive agents, crosslinking agents, hydrophiliccoatings, and associated reagents are disclosed in U.S. Pat. No.8,513,320 (to Rooijmans et al.); U.S. Pat. No. 8,809,411 (to Rooijmans);and 2010/0198168 (to Rooijmans), the content of all of which is hereinincorporated by reference.

Natural polymers can also be used to form the hydrophilic base coat.Natural polymers include polysaccharides, for example, polydextrans,carboxymethylcellulose, and hydroxymethylcellulose; glycosaminoglycans,for example, hyaluronic acid; polypeptides, for example, solubleproteins such as collagen, albumin, and avidin; and combinations ofthese natural polymers. Combinations of natural and synthetic polymerscan also be used.

In some instances a tie layer can be used to form the hydrophilic baselayer. In yet other instances the tie layer can be added to thehydrophilic base layer. The tie layer can act to increase the adhesionof the hydrophilic base layer to the substrate. In other embodiments,the tie layer can act to increase adhesion of the hydrophobic activeagent to the hydrophilic base layer. Exemplary ties layers include, butare not limited to silane, butadiene, polyurethane and parylene. Silanetie layers are described in US Patent Publication 2012/0148852 (toJelle, et al.), the content of which is herein incorporated byreference.

In exemplary embodiments, the hydrophilic base layer can include tannicacid, polydopamine or other catechol containing materials.

Substrates

The substrate can be formed from any desirable material, or combinationof materials, suitable for use within the body. In some embodiments thesubstrate is formed from compliant and flexible materials, such aselastomers (polymers with elastic properties). Exemplary elastomers canbe formed from various polymers including polyurethanes and polyurethanecopolymers, polyethylene, styrene-butadiene copolymers, polyisoprene,isobutylene-isoprene copolymers (butyl rubber), including halogenatedbutyl rubber, butadiene-styrene-acrylonitrile copolymers, siliconepolymers, fluorosilicone polymers, polycarbonates, polyamides,polyesters, polyvinyl chloride, polyether-polyester copolymers,polyether-polyamide copolymers, and the like. The substrate can be madeof a single elastomeric material, or a combination of materials.

Other materials for the substrate can include those formed of polymers,including oligomers, homopolymers, and copolymers resulting from eitheraddition or condensation polymerizations. Examples of suitable additionpolymers include, but are not limited to, acrylics such as thosepolymerized from methyl acrylate, methyl methacrylate, hydroxyethylmethacrylate, hydroxyethyl acrylate, acrylic acid, methacrylic acid,glyceryl acrylate, glyceryl methacrylate, methacrylamide, andacrylamide; vinyls such as ethylene, propylene, vinyl chloride, vinylacetate, vinyl pyrrolidone, vinylidene difluoride, and styrene. Examplesof condensation polymers include, but are not limited to, nylons such aspolycaprolactam, polylauryl lactam, polyhexamethylene adipamide, andpolyhexamethylene dodecanediamide, and also polyurethanes,polycarbonates, polyamides, polysulfones, poly(ethylene terephthalate),polydimethylsiloxanes, and polyetherketone.

Beyond polymers, and depending on the type of device, the substrate canalso be formed of other inorganic materials such as metals (includingmetal foils and metal alloys), glass and ceramics.

Processes to modify substrates described above can include chemicalmodifications to improve performance characteristics of the substrate.Specific chemical processes that can be used include ozone treatment,chemical oxidation, acid chemical etching, base chemical etching, plasmatreatment and corona treatment, surface grafting, thermally activatedcoating processes (both covalent and non-covalent) and surfacemodifications including coatings containing dopamine, tannic acid, plantpolyphenols and other catechols or catechol containing derivatives ofhydrophilic moieties. Additionally, processes to form substratesdescribed above can include physical modifications for example, but notlimited to, sand blasting and surface texturing (for example eitherduring or after the molding process of polymers).

In some embodiments, the modification of substrates as described hereincan allow for omission of a base coating layer (such as a hydrophiliclayer) as substrate surfaces that have been modified will allow forimproved adhesion of a hydrophobic therapeutic agent and cationic agentcompared with that of a hydrophilic layer.

Devices

It will be appreciated that embodiments herein include, and can be usedin conjunction with, various types of devices including, but not limitedto, drug delivery devices such as drug eluting balloon catheters,drug-containing balloon catheters, stents, grafts, and the like.

Some embodiments described herein can be used in conjunction withballoon expandable flow diverters, and self-expanding flow diverters.Other embodiments can include uses in contact with angioplasty balloons(for example, but not limited to, percutaneous transluminal coronaryangioplasty and percutaneous transluminal angioplasty). Yet otherembodiments can include uses in conjunction with sinoplasty balloons forENT treatments, urethral balloons and urethral stents for urologicaltreatments and gastro-intestinal treatments (for example, devices usedfor colonoscopy). Hydrophobic active agent can be transferred to tissuefrom a balloon-like inflatable device or from a patch-like device. Otherembodiments of the present disclosure can further be used in conjunctionwith micro-infusion catheter devices. In some embodiments,micro-infusion catheter devices can be used to target active agents tothe renal sympathetic nerves to treat, for example, hypertension.

Embodiments included herein can also be used in conjunction with theapplication of various active agents to the skin (for example, but notlimited to transdermal drug delivery).

Other exemplary medical applications wherein embodiments of the presentdisclosure can be used further encompass treatments for bladder neckstenosis (e.g. subsequent to transurethral resection of the prostrate),laryngotrachial stenosis (e.g. in conjunction with serial endoscopicdilatation to treat subglottic stenosis, treatment of oral cancers andcold sores and bile duct stenosis (e.g. subsequent to pancreatic,hepatocellular of bile duct cancer). By way of further example,embodiments herein can be used in conjunction with drug applicators.Drug applicators can include those for use with various procedures,including surgical procedures, wherein active agents need to be appliedto specific tissue locations. Examples can include, but are not limitedto, drug applicators that can be used in orthopedic surgery in order toapply active agents to specific surfaces of bone, cartilage, ligaments,or other tissue through physical contact of the drug applicator withthose tissues. Drug applicators can include, without limitation,hand-held drug applicators, drug patches, drug stamps, drug applicationdisks, and the like.

In some embodiments, drug applicators can include a surface having ahydrophilic polymer layer disposed thereon and coated therapeutic agentparticles disposed on the hydrophilic polymer layer, the coatedtherapeutic agent particles comprising a particulate hydrophobictherapeutic agent; and a cationic agent disposed over the particulatehydrophobic therapeutic agent.

In use, various embodiments included herein can enable rapid transfer oftherapeutic agents to specific targeted tissues. For example, in someembodiments, a care provider can create physical contact between aportion of a drug delivery device including a therapeutic agent and thetissue being targeted and the therapeutic agent will be rapidlytransferred from the drug delivery device to that tissue. As such,precise control over which tissues the therapeutic agent is provided tocan be achieved.

One beneficial aspect of various embodiments described herein is thatthe therapeutic agent can be transferred from the drug delivery deviceor coating to the targeted tissue very rapidly. In some embodimentssubstantial transfer of the therapeutic agent from the drug deliverydevice or coating to the tissue occurs in 30 minutes or less. In someembodiments substantial transfer of the therapeutic agent from the drugdelivery device or coating to the tissue occurs in 15 minutes or less.In some embodiments substantial transfer of the therapeutic agent fromthe drug delivery device or coating to the tissue occurs in 10 minutesor less. In some embodiments substantial transfer of the therapeuticagent from the drug delivery device or coating to the tissue occurs in 5minutes or less. In some embodiments substantial transfer of thetherapeutic agent from the drug delivery device or coating to the tissueoccurs in 2 minutes or less. In some embodiments substantial transfer ofthe therapeutic agent from the drug delivery device or coating to thetissue occurs in 1 minute or less.

Additional Embodiments

As described above, some embodiments can include a hydrophilic base coator layer. In some embodiments, a hydrophilic polymer solution is formedby combining a hydrophilic polymer with one or more solvents. Exemplaryhydrophilic polymers are described in greater detail above. Thehydrophilic polymer solution can then be applied to a suitablesubstrate, such as an expandable balloon disposed on a catheter shaft.Many different techniques can be used to apply the hydrophilic polymersolution to the substrate. By way of example, exemplary techniques caninclude brush coating, drop coating, blade coating, dip coating, spraycoating, micro-dispersion, and the like.

In some embodiments, such as where a photo-polymer is used to form thehydrophilic layer, an actinic radiation application step can beperformed in order to activate latent photoreactive groups on thehydrophilic polymer or on a crosslinker in order to covalently bond thehydrophilic polymer the substrate surface. By way of example, afterapplying the hydrophilic polymer solution to the substrate, the devicecan be subjected to UV exposure at a desirable wavelength for a periodof time.

Next a hydrophobic active agent can be obtained and processed in orderto prepare it for deposition. In some embodiments, processing of thehydrophobic active agent can include steps such as milling of the activeagent. In some embodiments, processing of the hydrophobic active agentcan include steps such as recrystallization of the active agent. In someembodiments, processing of the hydrophobic active agent can includelyophilizing of the active agent.

In various embodiments, the hydrophobic active agent, as a particulate,can be suspended in water. Using the hydrophobic active agent and acationic agent, coated therapeutic agent particles can be formed. By wayof example, a cationic agent, in water or a different solvent, can beadded to the hydrophobic active agent suspension. In variousembodiments, a mixing or agitation step can be performed in order toallow the hydrophobic active agent to interface with the cationic agent.In some embodiments, the cationic agent will surround the particulatehydrophobic active agent.

In some embodiments, a nucleic acid solution can be added to themixture, either before or after addition of the cationic agent and themixing/agitation steps. In some embodiments, an additive component suchas those described above can be added to the mixture. The mixture can beapplied to the substrate of a device, either directly or on top of ahydrophilic base coat. By way of example, exemplary techniques forapplication can include brush coating, drop coating, blade coating, dipcoating, spray coating, micro-dispersion and the like

After application, the composition can be allowed to dry. In the contextof drug eluting balloon catheters or a drug-containing balloon catheter,for example, the balloons can be folded, pleated and sheathed in asheath. In some embodiments, balloons can be placed in an oven for aperiod of time.

In some embodiments of the present disclosure, an active agent that isnot hydrophobic can be modified to be essentially hydrophobic fordisposition on the hydrophilic polymer layer. Exemplary modificationscan include the preparation of prodrugs, whereby the hydrophobicity ofthe active agent can be modified by covalent linkage to a polymer. Otherexemplary prodrugs can include an active agent that is formed in-situ bybond cleavage of the prodrug. Other exemplary modifications can include,but are not limited to, particles (e.g. nanoparticles or microparticles)containing the active agent encapsulated in a hydrophobic polymer. Insome embodiments the hydrophobic polymer can be biodegradable, releasingthe active agent upon delivery to the targeted tissue. Other exemplarymodifications can include, but are not limited to, micelles or otherconstructs of the like with altered hydrophobicity, formed as a resultof the interaction between the active agent and a lipid additive.

Microparticle preparations of the present disclosure can includeadditional excipients to modify the surface of the microparticle for aparticular application. For example, surface modifications to themicroparticle resulting in a microparticle with a positive or negativezeta-potential may be advantageous. Exemplary materials that can be usedto modify the zeta-potential of the surface of the microparticleinclude, but are not limited to polyacrylic acid (PAA), polyglutamicacid, polyaspartic acid, heparin, alginate, hyaluronic acid andpolyvinylsulfonic acid. Cationic polymers described above can also beexemplary materials used to modify the zeta-potential of the surface ofthe microparticle.

The present invention may be better understood with reference to thefollowing examples. These examples are intended to be representative ofspecific embodiments of the invention, and are not intended as limitingthe scope of the invention.

EXAMPLES Example 1: Paclitaxel Preparation and Balloon Coating Procedure

“Jar-Milled Paclitaxel”: Paclitaxel (LC laboratories) was suspended inwater at 65 mg/mL and milled using 5 mm stabilized zirconia 5×5 mmcylindrical beads (Stanford Materials Corp). After milling for 18 hoursthe slurry was removed from the beads and lyophilized.

“Sonicated Paclitaxel”: Paclitaxel crystals were obtained by suspendingpaclitaxel (LC Laboratories) in water at 50 mg/mL. The paclitaxel wasmicronized using a sonic probe for 30 seconds, and leaving the resultingsuspension for three days at room temperature on an orbital shaker witha 1 hour sonication treatment per day in a sonic bath over the course ofthe three days. The mixture was lyophilized.

Unless otherwise indicated the following NYLON balloons were used in allstudies: 20×3.5 mm.

Hydrophilic basecoats (R) were deposited onto the nylon balloonsurfaces. The hydrophilic basecoat solution included 6.25 g/L polyvinylpyrrolidone (PVP) with benzoylbenzoic acid groups; 1.25 g/Lpolyacrylamide; 2.5 g/L PVP (K90); and 0.05 g/L photo-crosslinker; in asolvent solution of 85:15 water/isopropanol. For examples 1-15,crosslinkers were prepared as described in U.S. Pat. No. 6,278,018,Swan. For examples 16-24, crosslinkers were prepared as described in USPatent Application Publication 2012/0046384, Kurdyumov et al. and U.S.Pat. No. 6,278,018, Swan. After coating the basecoat material was driedat room temperature for 15 minutes and then irradiated with UV light for3 minutes.

Typically, for any given formulation, an amount of 3 μg/mm² paclitaxelfor coating on the balloons was attempted (which is 660 μg paclitaxelper balloon). The paclitaxel containing coating mixture was applied ontop of the cured hydrophilic basecoat (R) by means of a positivedisplacement pipette and dried using a hot air-gun.

All balloons were dried over night at room temperature. The balloonswere folded, pleated and sheathed in a nylon sheath. The balloons weresubsequently placed in a 55° C. oven for 1 hour.

Chemicals were obtained from Sigma Aldrich unless stated otherwise.Amounts (μg) of active agent transferred to the tissue and standarddeviations for Examples 2-15 are listed in Table 3. Amounts (μg) ofactive agent transferred to the tissue and standard deviations forExamples 16-24 are listed in Table 9.

Example 2: Formulations with DOTAP and siRNA

Jar milled lyophilized paclitaxel was suspended in water at 67 mg/mL. To100 μL suspension 31 μL DOTAP at 20 mg/mL in ethanol (Avanti PolarLipids) was added and sonicated for 10 minutes in a sonic bath. Then 4.4μL of 1 mM non-coding siRNA, 0.065 mg, was added. Three balloonsreceived a hydrophilic basecoat (R) and a paclitaxel containing topcoataccording to the procedure as described in Example 1. 8 μL of thepaclitaxel containing mixture was used for the topcoat.

To 130 μL of the paclitaxel/DOTAP/siRNA containing mixture 3.7 mgglycogen (available from VWR) was added (74 μL of a 50 mg/mL solution inwater). Four balloons received a hydrophilic basecoat (R) and apaclitaxel containing topcoat with glycogen according to the procedureas described in Example 1. The paclitaxel-containing mixture (8 μL) wasused for the topcoat.

All balloons were dried over night at room temperature. The balloonswere folded, pleated and sheathed in a nylon sheath. The balloons weresubsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the following procedure. Excised pig coronary arteries (Pel-FreezBiologicals) were prepared and kept at 37° C. Upon removal of thesheaths from the balloons, the balloons were soaked in PBS at 37° C. for30 seconds and then removed from the PBS. Next, the balloon was expandedin the artery tissue at 60-80 psi for 30 seconds at 37° C. and afterdeflation and removal of the balloon, the artery tissue was rinsed withPBS at 37° C. After removal of the balloon from the tissue and rinsing,the tissue was placed in a methanol/0.1% acetic acid solution. Theresulting methanol and acetic acid solution was tested for paclitaxelcontent using HPLC (“Drug Transfer to Tissue”).

Example 3: Formulations with DOTAP and siRNA Formulation 1—“PAX+DOTAP1x”

Jar milled paclitaxel was suspended in water at 65 mg/mL and treatedwith a sonic probe for 30 seconds. 100 mg of the suspension (6.35 mgpaclitaxel) was weighed out and 32 μL DOTAP 20 mg/mL solution in ethanolwas added. The mixture was sonicated for 10 minutes. The balloonreceived a hydrophilic basecoat (R) and a paclitaxel containing topcoataccording to the procedure as described in Example 1. Thepaclitaxel-containing mixture (10 μL) was used for the topcoat.

Formulation 2—“PAX+DOTAP2x”

Jar milled paclitaxel was suspended in water at 65 mg/mL and treatedwith sonic probe for 30 seconds. 100 mg of the suspension (6.35 mgpaclitaxel) was weighed out and 64 μp L DOTAP 20 mg/mL solution inethanol was added. The mixture was sonicated for 10 minutes. The balloonreceived a hydrophilic basecoat (R) and a paclitaxel containing topcoataccording to the procedure as described in Example 1. Thepaclitaxel-containing mixture (10 μL) was used for the topcoat.

Formulation 3—“PAX+DOTAP1x+Si”

To formulation 1, 60 μg siRNA was added (4.2 μL 1 mM solution). Theballoon received a hydrophilic basecoat (R) and a paclitaxel containingtopcoat according to the procedure as described in Example 1. Thepaclitaxel-containing mixture (10 μL) was used for the topcoat.

Formulation 4—“PAX+DOTAP2x+si”

To formulation 2, 120 μg siRNA was added: 8.4 μL 1 mM solution. Theballoon received a hydrophilic basecoat (R) and a paclitaxel containingtopcoat according to the procedure as described in Example 1. Thepaclitaxel-containing mixture (10 μL) was used for the topcoat.

Formulation 5—“PAX+DOTAPIx+si+F68”

To formulation 3, 4 μL F68 @ 100 mg/mL in water was added (400 μg, ˜6%w/w total formulation). The balloon received a hydrophilic basecoat (R)and a paclitaxel containing topcoat according to the procedure asdescribed in Example 1. The paclitaxel containing mixture (10 μL) wasused for the topcoat.

Formulation 6—“PAX+DOTAP2x+si+F68”

To formulation 4, 4 μL F68 @ 100 mg/mL in water was added (400 μg, ˜6%w/w total formulation). The balloon received a hydrophilic basecoat (R)and a paclitaxel containing topcoat according to the procedure asdescribed in Example 1. The paclitaxel containing mixture (10 μL) wasused for the topcoat.

All balloons were dried over night at room temperature. The balloonswere folded, pleated and sheathed in a nylon sheath. The balloons weresubsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 4: Formulations with DOTAP

Jar-milled paclitaxel (as above) was used. Alternatively, paclitaxel wasmicronized using a Netsch micronizer, and freeze dried.

Paclitaxel Netsch milled particles were suspended at 67 mg/mL in waterand sonicated for 10 minutes.

Paclitaxel jar milled particles were suspended at 67 mg/mL in water andsonicated for 10 minutes.

Formulation 1

100 mg of the suspension of Netsch milled paclitaxel @ 67 mg/mL in DDW(6.28 mg paclitaxel) was weighed out and sonicated until well dispersed.DOTAP 20 mg/mL solution in ethanol (31.4 μL) was added and sonicated insonic bath for 10 minutes. Two balloons each received a hydrophilicbasecoat (R) and a paclitaxel containing topcoat according to theprocedure as described in Example 1. The paclitaxel-containing mixture(14 μL) was used for the topcoat.

Formulation 2

100 mg of the suspension of Netsch milled paclitaxel @ 67 mg/mL in DDW(6.28 mg paclitaxel) was weighed out and sonicated until well dispersed.0.628 mg DOTAP (31.4 μL DOTAP 20 mg/mL in ethanol) was added andsonicated in sonic bath for 10 minutes. Then 0.063 mg siRNA: 4.4 μLsiRNA @ 1 mM, 14.2 mg/ml was added and vortexed well; sonicated for 5minutes. 4 μL F68 at 10 mg/ml in water was added. Two balloons eachreceived a hydrophilic basecoat (R) and a paclitaxel containing topcoataccording to the procedure as described in Example 1. The paclitaxelcontaining mixture (15 μL) was used for the topcoat.

Formulation 3

100 mg of the suspension of jar milled paclitaxel @ 67 mg/mL in DDW(6.28 mg paclitaxel) was weighed out and sonicated until well dispersed.31.4 μL DOTAP 20 mg/mL solution in ethanol was added and sonicated insonic bath for 10 minutes. Two balloons each received a hydrophilicbasecoat (R) and a paclitaxel containing topcoat according to theprocedure as described in Example 1. The paclitaxel-containing mixture(14 μL) was used for the topcoat. Only one balloon was tested.

Formulation 4

200 mg of the suspension of jar milled paclitaxel @ 67 mg/mL in DDW(12.56 mg paclitaxel) was weighed out and sonicated until welldispersed. 2.51 mg DOTAP (126 μL DOTAP 20 mg/mL in ethanol) was addedand sonicated in sonic bath for 10 minutes. Two balloons each received ahydrophilic basecoat (R) and a paclitaxel containing topcoat accordingto the procedure as described in Example 1. The paclitaxel containingmixture (17.5 μL) was used for the topcoat.

Formulation 5

100 mg of the suspension of jar milled paclitaxel @ 67 mg/mL in DDW(6.28 mg paclitaxel) was weighed out and sonicated until well dispersed.0.628 mg DOTAP (31.4 μL DOTAP 20 mg/mL in ethanol) was added andsonicated in sonic bath for 10 minutes. 4 μL F68 at 10 mg/ml in waterwas added (0.6% vs paclitaxel, or total). Two balloons each received ahydrophilic basecoat (R) and a paclitaxel containing topcoat accordingto the procedure as described in Example 1. The paclitaxel containingmixture (15 μL) was used for the topcoat.

Formulation 6

130 μL of formulation 4 was transferred to a new tube and added 4 μL F68at 100 mg/mL in water (0.5%). Two balloons received a hydrophilicbasecoat (R) and a paclitaxel containing topcoat according to theprocedure as described in Example 1. The paclitaxel-containing mixture(17.5 μL) was used for the topcoat.

Formulation 7

200 mg of the suspension of jar milled paclitaxel at 67 mg/mL in DDW(12.56 mg paclitaxel) was weighed out and sonicated until welldispersed. 1.26 mg DOTAP: 63 μL DOTAP 20 mg/mL in ethanol was added andsonicated in sonic bath for 10 minutes. Then 0.126 mg siRNA: 8.8 μLsiRNA at 1 mM, 14.2 mg/ml was added and vortexed well; sonicated for 5minutes. 8 μL F68 at 10 mg/ml in water was added. Two balloons eachreceived a hydrophilic basecoat (R) and a paclitaxel containing topcoataccording to the procedure as described in Example 1. of the paclitaxelcontaining mixture (15 μL) was used for the topcoat.

All balloons were dried over night at room temperature. The balloonswere folded, pleated and sheathed in a nylon sheath. The balloons weresubsequently placed in a 55° C. oven for 1 hour. Release of thepaclitaxel from the coating was then assessed according to the procedureas described in example 2.

Example 5: Coating Transfer from Rods

The top surface of 5 cm long rods having a 5 mm diameter were coatedwith the hydrophilic base coat (R) as described above. The coating wasapplied by brushing the surfaces of the rods with the solution, dryingfor 15 minutes at room temperature and subsequently irradiating for 3minutes with UV. Three formulations were prepared:

Formulation 1

Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100 mg of thesuspension (6.28 mg paclitaxel) was weighed out and sonicated until welldispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20 mg/mL in ethanol) was addedand sonicated in sonic bath for 10 minutes.

Formulation 2

Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100 mg of thesuspension (6.28 mg paclitaxel) was weighed out and sonicated until welldispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20 mg/mL in ethanol) was addedand sonicated in sonic bath for 10 minutes. Then F68 was added 5% w/wtotal formulation as a 100 mg/mL solution in water

Formulation 3

Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100 mg of thesuspension (6.28 mg paclitaxel) was weighed out and sonicated until welldispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20 mg/mL in ethanol) was addedand sonicated in sonic bath for 10 minutes. Then 62.8 μL dextran (100mg/mL in water) was added.

In triplicate, the rods received the paclitaxel containing topcoat bypipetting 5 μL of one of the formulations and letting dry at roomtemperature overnight.

Ex vivo pig skin tissue was trimmed from fat and excised with a 8 mmtissue excision tool (Sklar) and kept at 37° C. The rods were soaked for30 seconds in PBS at 37° C. Subsequently the rods were impressed intothe excised tissue for 30 seconds. The tissue samples were placed in amethanol/0.1% acetic acid solution in a vial with tissue disruptionmedia. The tissue was disrupted to extract transferred paclitaxel

Example 6: Varying Ratios of Components

10 NYLON balloon stubs received a hydrophilic basecoat (R) according tothe procedure as described in Example 1.

Jar-milled paclitaxel was suspended in water at 65 mg/mL. DOTAPdissolved in ethanol at 25 mg/mL was added to the formulation at 20 or40% w/w paclitaxel and sonicated in sonic bath for 10 minutes. To someof the resulting mixtures gelatine B, glycogen or dextran was added as a100 mg/mL solution in water at 33% or 50% w/w total matrix. Theformulations were applied as a topcoat on the balloon (following theprocedure in Example 1), aiming for approximately for a total of 700 μgpaclitaxel in the coating. The balloons were folded, pleated andsheathed in a nylon sheath. The balloons were subsequently placed in a55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 7: Formulations with PLURONIC® F68

Formulations were prepared by suspending jar-milled paclitaxel in waterat 65 mg/mL. DOTAP dissolved in ethanol at 25 mg/mL was added to theformulation at 20% w/w paclitaxel. To the resulting mixtures PLURONIC®F68 (BASF Corporation) was added as a 10 or 100 mg/mL solution in water,reaching 0.6-5% w/w of the total matrix. The formulations weretop-coated on balloons with hydrophilic base-coats R as described inexperiment 1.

All balloons were dried over night at room temperature. The balloonswere folded, pleated and sheathed in a nylon sheath. The balloons weresubsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 8: Amorphous Paclitaxel Nanoparticles with DOTAP orPolvethyleneimine

(i) Preparation of amorphous paclitaxel particles: In triplicate, anaverage of 6.2 mg of paclitaxel was dissolved in 50 μL chloroform. Thesolution was dispersed in 1 mL BSA at 50 mg/mL in water using a sonicprobe for 20 seconds. The obtained emulsions were spun in a centrifugefor 15 minutes at 5000 rpm. The clear supernatant was aspirated; theresidue was frozen and lyophilized. The residues weighed on average 9.8mg. To remove the remaining BSA, the solids were dispersed in 1 mL offresh water using a sonic bath and subsequently spun for 10 minutes at10,000 rpm. The supernatant was aspirated.

-   -   (ii) Preparation of DOTAP dispersion in water:    -   5 mL of a DOTAP solution at 25 mg/mL in ethanol was placed in a        glass round-bottom container and evaporated under vacuum to        obtain a film. The DOTAP was dispersed in 12.5 mL water by        adding batches of 4.2 mL water to the glass container and        briefly sonication in a sonic bath. The batches were combined,        sonicated for 10 minutes in a sonic bath and filtered through a        0.45 μm filter.

Balloons were base- and top-coated following the procedure described inExample 1. In order to obtain the formulations for the paclitaxelcontaining topcoats, DOTAP dispersed in water or an aqueous solution ofPEI was added to the obtained amorphous paclitaxel particles as follows:

-   -   1. 114 μL of a DOTAP dispersion in water at 10 mg/mL was added        to 5.7 μg paclitaxel. 15 μL was used to coat balloon material,    -   2. 62 μL polyethyleneimine low molecular weight (PEI-LMW) at 20        mg/mL with 31 μL water was added to 6.2 μg paclitaxel. 10 μL was        used to coat balloon material,    -   3. 67 μL polyethyleneimine 750 kDa (PEI-HMW) at 20 mg/mL with 33        μL water was added to 6.7 μg paclitaxel. 10 μL was used to coat        balloon material.

All balloons were dried over night at room temperature. The balloonswere folded, pleated and sheathed in a nylon sheath. The balloons weresubsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 9: Z-Potential Measurements

Paclitaxel (5 mg) was dissolved in 10 μL benzyl alcohol. The solutionwas dispersed in 1 mL BSA at 50 mg/mL in water using a sonic probe for20 seconds. The obtained emulsion was divided into 5 times 200 μLportions which were spun in a centrifuge for 10 minutes at 10000 rpm(residuals A-E). The clear supernatant was aspirated.

-   -   A. The residue was resuspended in 1 mL of DDW. This mixture was        diluted 10 times.    -   B. 10 μL of a chitosan solution 10 mg/mL in 1% acetic acid was        added with 10 μL DDW. The resulting suspension was diluted in        DDW 10 times.    -   C. 1 mL of a protamine solution 1 mg/mL in DDW was added. The        resulting suspension was diluted in DDW 10 times.    -   D. The solids were dispersed in 500 μL of DDW using a sonic bath        and subsequently spun for 10 minutes at 10,000 rpm. The        supernatant was aspirated. 5 mL of a DOTAP solution at 25 mg/mL        in ethanol was placed in a glass round-bottom container and        evaporated under vacuum to obtain a film. The DOTAP was        dispersed in 12.5 mL water by adding batches of 4.2 mL water to        the glass container and briefly sonication in a sonic bath. The        batches were combined, sonicated for 10 minutes in a sonic bath        and filtered through a 0.45 μm filter. To the amorphous        paclitaxel residue 25 μL of a DOTAP dispersion in water at 10        mg/mL was added and sonicated in sonic bath. The resulting        dispersion was diluted in DDW 10 times.

Z-sizing measurements were taken using a Z-sizer (available fromMalvern) showing the formation of negatively charged droplets upondispersion of dissolved PTX in a BSA solution. Positively chargedparticles were obtained upon addition of chitosan, protamine or DOTAPsolutions.

TABLE 2 Temperature (° C.) and ZP values (mV) for Example 9. Sample NameT (° C.) ZP (mV) PTX/BSA in Water 25 −23.1 Chitosan 25 +63.8 DOTAP 25+58 Protamine 37 +12.3

Example 10: F68 on PTX/DOTAP Formulation

Formulations were prepared by suspending jar-milled paclitaxel in waterat 65 mg/mL. DOTAP dissolved in ethanol at 25 mg/mL was added to theformulation at 20% w/w paclitaxel. To the resulting mixtures F68 wasadded 2-16 μL at 100 mg/mL solution in water, reaching 5-34% w/w of thetotal matrix (50% w/w PTX). The balloon stubs were base- and top-coatedfollowing the procedure described in example 1. Additionally a PTX/DOTAP80:20% w/w formulation was tested. The formulations were top-coated onballoon stubs with hydrophilic base-coat F (n=2 per formulation).

The balloons were folded, pleated and sheathed in a nylon sheath. Theballoons were subsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 11: Use of Amorphous PTX and Different Cationic Moieties

Four balloons were base- and top-coated following the proceduredescribed in experiment 1. The following formulations were top-coated onballoon-stubs with hydrophilic base-coat R. (n=1 per formulation).

In each of 4 tubes 5-7 mg of paclitaxel was dissolved in 50 μLchloroform. The solution was dispersed in 1 mL BSA at 50 mg/mL in waterusing a sonic probe for 20 seconds. The obtained emulsions were spun ina centrifuge for 10 minutes at 5000 rpm.

The clear supernatant was aspirated and the residue was frozen on dryice and subsequently lyophilized. (“paclitaxel residue”).

-   -   A. Started with 4.8 μg paclitaxel. Paclitaxel residue was        reconstituted in 96 μL DDW. 14 μL was used to coat balloon        material.    -   B. Started with 7.1 μg paclitaxel. Residual BSA was removed by        dispersing the solids in 1 mL of fresh water using a sonic bath        and subsequently spun for 10 minutes at 10,000 rpm. The        supernatant was aspirated. 5 mL of a DOTAP solution at 25 mg/mL        in ethanol was placed in a glass round-bottom container and        evaporated under vacuum to obtain a film. The DOTAP was        dispersed in 12.5 mL water by adding batches of 4.2 mL water to        the glass container and briefly sonication in a sonic bath. The        batches were combined, sonicated for 10 minutes in a sonic bath        and filtered through a 0.45 μm filter. 142 μL of the DOTAP        dispersion in water at 10 mg/mL was added to the paclitaxel        residue. 14 μL was used to coat balloon material.    -   C. Started with 7.1 μg paclitaxel. Chitosan was dissolved in 1%        acetic acid at 100 mg/mL and 57 μL was added to the paclitaxel        residue. Then 57 μL DDW was added. Particles were dispersed        using a sonic bath. The balloon was coated with 14 μL of this        material.    -   D. Started with 5.1 μg paclitaxel. Protamine was dissolved in        DDW at 10 mg/mL. 51 μL of the protamine solution was added with        additional 51 μL DDW to the paclitaxel residue. Particles were        dispersed using a sonic bath. The balloon was coated with 14 μL        of this material.

The balloons were folded, pleated and sheathed in a nylon sheath. Theballoons were subsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2

Example 12: Study IV Flow Experiment

Full length balloon catheters received hydrophilic base coats asdescribed in experiment 1. Paclitaxel containing formulations werecoated on full length catheter balloons and tested in ex-vivo pigcoronary arteries in the flow experiment.

-   -   1.) Flow systems: Two open flow loops of PBS in the system were        used. One, circulating at 70 mL/min, 2 L total and at 37° C. was        for the artery in which the balloon is 25 tested. The other, at        280 mL/min, μL total and at 37° C., was for a manifold that        supported four arteries at once (flow at the output was thus 70        mL/min).    -   2.) Artery connections: Pig coronary arteries for testing were        prepared by trimming and gluing (with a cyanoacrylate gel glue        (“super glue”)) onto a 200 μL pipette tip. The tip was trimmed        on the short end such that the opening in the tip was ˜2-3 mm in        diameter. After gluing, arteries were trimmed to be 30 mm from        the end of the pipette tip to the free end of the artery.        Arteries were held in PBS at room temperature prior to testing.

Each piece of tubing terminated in a 1 mL pipette tip that served as ameans to affix arteries. At the test site, the tip was trimmed to fitinto the tubing at the large end and to be larger than the diameter ofthe 7F guide catheter at the small end. In the manifold, the tips weretrimmed to fit snugly on the Y-connectors on the large end but were nottrimmed on the small end. The resistance provided by the small tiporifice ensured equal flow through the four ports.

For testing, arteries were put onto the end of the flow tubing bypress-fitting the smaller yellow pipette tip onto the larger blue tip.

10 mL PBS was drawn into the syringe (on hemostat Y connector) andflushed through the guide catheter to ensure the catheter was filledwith PBS. The prepared pig coronary artery was placed on the test loopby pressing it onto the pipette end. Then coated balloon catheter wasintroduced as the hemostat was opened wide. The catheter was pushed tothe point where the guide exited the catheter and the guidewire wasremoved. The hemostat was closed somewhat to reduce backflow. Then theballoon catheter was pushed to the treatment site inside the preparedcoronary artery and the hemostat was closed tightly. The balloon wasinflated to 6 ATM and held for 30 seconds. The hemostat was opened andthe balloon catheter was deflated and removed. The artery was thenremoved from test loop and placed on second flow manifold (one of fourspaces) and left for on flow manifold for 13 minutes, counted from timeof deflation of the balloon. The artery was cut from pipette tip placedin a methanol/0.1% acetic acid solution. The resulting methanol andacetic acid solution was tested for paclitaxel content using HPLC (“DrugTransfer to Tissue”).

Example 13: Release of Paclitaxel from Full Length Balloon Catheters

One full length balloon catheter and 2 balloon stubs received ahydrophilic basecoat (R) according to example 1 and were coated with thefollowing formulations:

-   -   A) Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100        mg of the suspension (6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20        mg/mL in ethanol) was added and sonicated in sonic bath for 10        minutes. Then 62.8 μL dextran (100 mg/mL in water) was added.        The balloon was coated with 22.5 μL of this material.    -   B) Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100        mg of the suspension (6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20        mg/mL in ethanol) was added and sonicated in sonic bath for 10        minutes. Then 62.8 μL glycogen (100 mg/mL in water) was added.        The balloon was coated with 22.5 μL of this material.    -   C) Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100        mg of the suspension (6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20        mg/mL in ethanol) was added and sonicated in sonic bath for 10        minutes. A solution of gelatin type A (100 mg/mL in water) was        warmed to 37° C. Then 62.8 μL was added to the mixture. The        balloon was coated with 22.5 μL of this material.    -   D) Jar-milled paclitaxel was suspended in water at 67 mg/mL. The        suspension (100 mg; 6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. A mixture of 953 μg DOTAP and        318 μg cholesterol in 51 μL ethanol was added and sonicated in        sonic bath for 10 minutes. The balloon was coated with 15.5 μL        of this material.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were then folded, pleated and sheathedin a nylon sheath. The balloons were subsequently placed in a 55° C.oven for 1 hour.

The full length catheter was tested according to the procedure inexample 12.

Release of the paclitaxel from the coating on the two balloon stubs wasassessed according to the procedure as described in example 2.

Example 14: Release of Paclitaxel from Balloons

Three full-length balloon catheters per formulation received ahydrophilic basecoat (R) according to example 1 and were top-coated withthe following formulations:

-   -   A) Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100        mg of the suspension (6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20        mg/mL in ethanol) was added and sonicated in sonic bath for 10        minutes. Then 62.8 μL dextran (100 mg/mL in water) was added.        The balloon was coated with 22.5 μL of this material.    -   B) Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100        mg of the suspension (6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20        mg/mL in ethanol) was added and sonicated in sonic bath for 10        minutes. Then 62.8 μL glycogen (100 mg/mL in water) was added.        The balloon was coated with 22.5 μL of this material.    -   C) Jar-milled paclitaxel was suspended in water at 67 mg/mL. 100        mg of the suspension (6.28 mg paclitaxel) was weighed out and        sonicated until well dispersed. 1.26 mg DOTAP (62.8 μL DOTAP 20        mg/mL in ethanol) was added and sonicated in sonic bath for 10        minutes. To the resulting mixture PLURONIC® F68 (available from        BASF Corporation) was added as a 100 mg/mL solution in water,        reaching 5% w/w of the total coating formulation.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were then folded, pleated and sheathedin a nylon sheath. The balloons were subsequently placed in a 55° C.oven for 1 hour.

The full length catheters were tested according to the procedure inexample 12.

Example 15: Release of Paclitaxel from Balloons

Three full-length balloon catheters per formulation received thehydrophilic basecoat (R) according to example 1 and were top-coated withthe following formulations:

Per formulation, 5-6 mg of paclitaxel was dissolved in 50 μL chloroform.The solution was dispersed in 1 mL BSA at 50 mg/mL in water using asonic probe for 20 seconds. The obtained emulsions were spun in acentrifuge for 15 minutes at 5000 rpm. The clear supernatant wasaspirated; the residue was frozen and lyophilized. The residues weighedon average 9.8 mg. To remove the remaining BSA, the solids weredispersed in 1 mL of fresh water using a sonic bath and subsequentlyspun for 10 minutes at 10,000 rpm. The supernatant was aspirated(“paclitaxel residue”).

5 mL of a DOTAP solution at 25 mg/mL in ethanol was placed in a glassround-bottom container and evaporated under vacuum to obtain a film. TheDOTAP was dispersed in 12.5 mL water by adding batches of 4.2 mL waterto the glass container and briefly sonication in a sonic bath. Thebatches were combined, sonicated for 10 minutes in a sonic bath andfiltered through a 0.45 μm filter.

Polyethyleneimine at high molecular weight 50% w/w in water (Sigma) wasdiluted in DDW to a 2% w/w or 20 mg/mL solution.

To the amorphous paclitaxel residues DOTAP or PEI in water was added asfollows:

-   -   1. (5 μg paclitaxel) 100 μL of a DOTAP dispersion in water at 10        mg/mL was added to the paclitaxel residue. 15.8 μL was used to        coat balloon material.    -   2. (6 μg paclitaxel) 60 μL polyethyleneimine high molecular        weight (PEI-HMW) at 20 mg/mL was added with 30 μL water. 11.8 μL        was used to coat balloon material.    -   3. (5 μg paclitaxel) 100 μL of a DOTAP dispersion in water at 10        mg/mL was added to the paclitaxel residue. Then 50 μL dextran        (100 mg/mL in water) was added. The balloon was coated with 23.8        μL of this material.    -   4. 5 mg jar-milled paclitaxel was suspended in 75 μL water and        sonicated until well dispersed. 1 mg DOTAP (40 μL DOTAP 25 mg/mL        in ethanol) was added and sonicated in sonic bath for 10        minutes. 18.2 μL was used to coat balloon material.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were then folded, pleated and sheathedin a nylon sheath. The balloons were subsequently placed in a 55° C.oven for 1 hour.

The full length catheters were tested according to the procedure inexample 12.

TABLE 3 Tissue Transfer (μg) and Standard Deviations for Examples 2-15.Active Agent Stand- Tissue ard transfer Devi- Example Description (μg)ation Example 2 PTX/DOTAP/SIRNA 42.05 15.09 PTX/DOTAP/siRNA/glycogen71.29 13.71 Example 3 PTX + DOTAP 10% w/w 88.44 PTX + DOTAP 20% w/w102.68 PTX + DOTAP 10% w/w + siRNA 116.92 PTX + DOTAP 20% w/w + siRNA107.64 PTX + DOTAP 10% w/w + siRNA + 152.2 F68 PTX + DOTAP 20% w/w +siRNA + 109.8 F68 Example 4 PTX(Netsch milled)/DOTAP 10:1 w/w 112.7040.76 (formulation 1) PTX(Netsch milled)/ 112.50 6.70 DOTAP/F68/siRNA10:1:0.5:0.1 w/w (formulation 2) PTX(Jar milled)/DOTAP 10:1 w/w 82.40(formulation 3) PTX(Jar milled)/DOTAP 5:1 w/w 154.82 80.47 (formulation4) PTX(Jar milled)/DOTAP/F68 10:1:0.5 157.80 10.13 w/w (formulation 5)PTX(Jar milled)/DOTAP/F68 5:1:0.5 178.94 0.08 w/w (formulation 6)PTX(Jar milled) /DOTAP/F68/siRNA 122.64 8.26 5:1:0.5:0.1 w/w(formulation 7) Example 5 PTX/DOTAP 5:1 107.21 18.76 PTX/DOTAP/F685:1:0.16 99.06 12.44 PTX/DOTAP/Dext 5:1:5 116.21 3.34 Example 6PTX/DOTAP 15:6 w/w 107.8 PTX/DOTAP/Gelatine B 15:3:5 w/w 80.12PTX/DOTAP/Gelatine B 15:6:5 w/w 78.4 PTX/DOTAP/Gelatine B 15:3:5 w/w79.2 PTX/DOTAP/Glycogen 15:3:15 w/w 293.32 PTX/DOTAP/Glycogen 15:3:5 w/w116.32 PTX/DOTAP/Glycogen 15:6:5 w/w 80.88 PTX/DOTAP/Dextran 15:3:5 w/w128.76 PTX/DOTAP/Dextran 15:6:5 w/w 125.92 PTX/DOTAP/Dextran 15:3:15 w/w172.16 Example 7 PTX/DOTAP/F68 5:1:0.32 w/w 180.30 91.22 PTX/DOTAP/F685:1:0.16 w/w 148.46 41.83 PTX/DOTAP/F68 5:1:0.04 w/w 91.62 9.64 Example8 PTX(amorphous)/DOTAP 5:1 w/w 185.76 73.19 PTX(amorphous)/PEI-LMW 5:1w/w 69.96 30.79 PTX(amorphous)/PEI-HMW 5:1 w/w 260.63 168.15 Example 10PTX/DOTAP 5:1 139.8 6.2 PTX/DOTAP/F68 5:1:0.32 w/w 151.7 48.8PTX/DOTAP/F68 5:1:0.65 w/w 80.8 12.6 PTX/DOTAP/F68 5:1:1.3 w/w 69.9 4.9PTX/DOTAP/F68 5:1:2.6 w/w 86.7 17.1 Example 11 PTX only 62.08 PTX/DOTAP5:1 w/w 282.36 PTX/chitosan 10:1 w/w 48.32 PTX/Protamine 10:1 w/w 60.68Example 13 PTX/DOTAP/DEXTRAN static test 116.94 5.23 PTX/DOTAP/DEXTRANflow test 75.84 PTX/DOTAP/gelatine A static test 69.18 28.60PTX/DOTAP/gelatine A flow test 7.20 PTX/DOTAP/glycogen static test118.00 38.41 PTX/DOTAP/glycogen flow test 60.24 PTX/DOTAP/Cholesterolstatic test 103.98 3.87 PTX/DOTAP/Cholesterol flow test 40.64 Example 14PTX/DOTAP/F68 79:16:5 w/w 68.97 29.08 PTX/DOTAP/glycogen 45.5:9:45.572.57 19.14 w/w PTX/DOTAP/dextran 45.5:9:45.5 w/w 83.28 38.72 Example 1583% PTX(amorphous)/17% DOTAP 35.89 7.50 w/w 83% PTX(amorphous)/17% PEI-65.94 12.57 HMW w/w 45.5% PTX(amorphous)/9% DOTAP/ 75.67 14.09 45.5%dextran w/w 83% PTX(jar milled)/17% DOTAP 49.12 13.83 w/w

Example 16: PEI and PAMAM Dendrimers

Twelve balloon stubs were coated with the hydrophilic base coat (R) asdescribed in Example 1. The following formulations were applied on topof the basecoat:

-   -   Stub #1 and #2: coating was applied from a 25% ethanol/75%        methanol solution containing 75 mg/mL paclitaxel and 6.25 mg/mL        polyethyleneimine (PEI-HMW) of 750 kDa. Total drug was targeted        at 660 μg.    -   Stub #3 and #4: coating was applied from a 25% ethanol/75%        methanol solution containing 75 mg/mL paclitaxel and 6.25 mg/mL        polyamidoamine dendrimer (PAMAM, Gen. 4). Total drug was        targeted at 660 μg.    -   Stub #5, #6 and #7: Paclitaxel was dissolved in chloroform at        100 mg/mL. 400 μL of this solution was emulsified in 10 mL        aqueous BSA solution at 50 mg/mL using a sonic probe for 60        seconds. The resulting emulsion was lyophilized. BSA was removed        15 from the amorphous paclitaxel by washing the solids three        times with double distilled water. To 6.5 mg amorphous        paclitaxel 33 μL water and 65 μL aqueous solution of PEI-HMW 20        mg/mL was added. The coating solution was vortexed and sonicated        on sonic bath. Coating the tubs total drug was targeted at 660        μg.    -   Stub #8, #9 and #10: To a mixture of 7 mg jar-milled paclitaxel        in 70 μL water was added 70 μL of an aqueous solution of PEI-HMW        at 20 mg/mL. Total drug was targeted at 660 μg.    -   Stub #11 and #12: Mixture of jar-milled paclitaxel at 50 mg/mL        in DDW with 10 mg/mL PAMAM in ethanol. PAMAM was added to the        paclitaxel suspension until reaching a wt/wt ratio of 17:83        PAMAM versus paclitaxel. Total drug was targeted at 660 μg.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were then folded, pleated and sheathedin a nylon sheath. The balloons were subsequently placed in a 55° C.oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 17: Release of Paclitaxel from Full Length Balloon Catheters

Nine full-length balloon catheters received a hydrophilic basecoat (R)according to example 1 and were top-coated with the followingformulations (n=3 per formulation):

-   -   1. 19 mg Jar-milled paclitaxel was combined with 283.6 μL        distilled water and twice sonicated using a sonic probe for 20        seconds at power setting “3”. 99.5 mg of the mixture was weighed        out and added 62.9 μL of a solution of PEI 750 kDa 20 mg/mL in        distilled water. Three catheters each were top-coated with 20.5        μL of the formulation.    -   2. 103.4 mg of the paclitaxel in water suspension was weighed        out. 65.4 μL of a 20 mg/mL PEI 750 kDa in water solution and        65.4 μL of a 100 mg/mL dextran solution in water was added.        Three catheters each were top-coated with 28 μL of the        formulation.    -   3. Amorphous paclitaxel was obtained according to the procedure        described in example 8, starting with 8 mg paclitaxel. To the        paclitaxel residue 80 μL PEI of a 20 mg/mL PEI 750 kDa in water        solution and 80 μL of a 100 mg/mL Dextran solution in water was        added. Three catheters were top-coated with 15.8 μL of the        formulation.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were then folded, pleated and sheathedin a nylon sheath. The balloons were subsequently placed in a 55° C.oven for 1 hour.

The full length catheters were tested according to the procedure inexample 12.

Release of the paclitaxel from the coating on the stubs was assessedaccording to the procedure as described in example 2.

Example 18A: Topcoat Balloon with Oleylamine

Eight balloon stubs of 15 mm length were coated with the hydrophilicbase coat (R) as described in Example 1. The following formulations wereapplied on top of the basecoat.

-   -   1. 49.5 mg Jar-milled pacltitaxel was suspended in 495 μL        distilled water, vortexed and sonicated twice with sonic probe        for 20 seconds. Then 495 μL PEI 750 kDa at 20 mg/mL, pH        neutralized to 7 with 6N HCl, was added. Two stubs were        topcoated with 10 μL of the formulation per stub.    -   2. Paclitaxel was dissolved in methanol at 100 mg/mL. To 50 μL        of the paclitaxel solution, 50 μL of a 25 mg/mL PEI 750 kDa        solution in ethanol was added. Two stubs were topcoated with 10        μL of the formulation per stub.    -   3. Oleylamine was dissolved in ethanol at 20 mg/mL. 25 μL was        added to 75 μL of the 100 mg/mL paclitaxel solution in methanol.        Two stubs were topcoated with 7 μL of the formulation per stub.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were then folded, pleated and sheathedin a nylon sheath. The balloons were subsequently placed in a 55° C.oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 18B: Topcoat Balloon with Polyurethanediol,Tricaprylmethylammonium Chloride, Trimethylolpropane Ethoxylate,Pentaerythritol Ethoxylate and Jeffamine ED-900

Ten balloon stubs of 15 mm length were coated with the hydrophilic basecoat (R) and top-coated as described in Example 1. The followingformulations were applied on top of the basecoat. 100 mg Jar-milledpaclitaxel was suspended in 1 mL distilled water and thoroughlydispersed using vortex and sonic probe.

-   -   1. Polyurethanediol 88 wt % was dissolved in water at 25 mg/mL.        55.7 mg of the paclitaxel suspension was weighed out and 40.7 μL        of the polyurethanediol solution was added. Two stubs were top        coated with 12.6 μL of the formulation per stub.    -   2. Tricaprylylmethylammonium chloride was dissolved in ethanol        at 25 mg/mL. 77.4 mg of the paclitaxel suspension was weighed        out and 56 μL of the Tricaprylylmethylammonium solution was        added. One stub was top coated with 12.6 μL of the formulation.    -   3. Trimethylolpropane ethoxylate 20/3 EO/OH was dispersed in        water at 25 mg/mL. 57.4 mg of the paclitaxel suspension was        weighed out and 41.7 μL of the trimathylolpropane ethoxylate        solution was added. Two stubs were top coated with 12.6 μL of        the formulation per stub.    -   4. Pentaerythritol ethoxylate 15/4 EO/OH was dissolved in water        at 25 mg/mL. 67.9 mg of the paclitaxel suspension was weighed        out and 49.4 μL of the Pentaerythritol ethoxylate solution was        added. Two stubs were topcoated with 12.6 μL of the formulation        per stub.    -   5. Jeffamine ED-900 was dissolved in water at 25 mg/mL. 59.8 mg        of the paclitaxel suspension was weighed out and 43.5 μL of the        Jeffamine solution was added. Two stubs were top coated with        12.6 μL of the formulation per stub.

The balloons were folded, pleated and sheathed in a nylon sheath. Theballoons were subsequently placed in a 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the procedure as described in example 2.

Example 19: Synthesized Linear and Branched PEI

The following compounds were synthesized based on dodecane-epoxylationof spermine, triethylamine glycol, 1-methyl-propyldiamine or other aminederivatives

Balloon stubs (22) were coated with the hydrophilic base coat (R) andreceived a topcoat as described in Example 1.

Preparation of formulations for the topcoats: Jar-milled paclitaxel wassuspended in water at 100 mg/mL and thoroughly dispersed using vortexand two times probe-sonication for 20 seconds at setting “2.5”. All ofthe following formulations were prepared by weighing out paclitaxelsuspension and adding a solution of an additive such that the w/w ratioof paclitaxel versus additive was 83:17% w/w. The resulting mixtureswere vortexed thoroughly and placed in a sonic bath for 10 minutes priorto applying the coating. Formulations (12.6 μL) were applied on top ofthe basecoat of each of 2 stubs and one metal coupon per formulation.The procedures for coating the stubs as described in example 1 werefollowed. The coatings on the metal coupons were weighed after thecoating was completely dry.

TABLE 4 Variable Values for Example 19. Paclitaxel Conc. Added Coatingsuspension (mg/ Solvent of Amount water weight Nr. (mg) Additive mL)additive (μL) (μL) (μg) 1 41 Trolamine 20 water 37.3 N/A 683 2 45.7Compound C 25 ethanol 33.2 83 777 3 41.1 Compound D 25 ethanol 29.9 7.5647 4 40.3 Compound E 25 ethanol 29.3 7.3 778 5 41.1 Linear PEI 20 warmwater 37.4 N/A 692 2.5 kDa 6 38.7 Linear PEI 20 warm water 35.2 N/A 65625 kDa 7 45.3 Linear PEI 20 warm water 41.2 N/A 717 250 kDa 8 38.9Branched PEI 20 water 35.4 N/A 822 1.2 kDa 9 44.7 Branched PEI 20 water40.6 N/A 774 10 kDa 10 52.0 Branched PEI 20 water 47.3 N/A 795 50-100kDa

Numbers 5-10 in Table 4 (PEI polymers) were purchased from Polysciences,Inc.

The coated balloon stubs were dried under hot air and left further todry over night at room temperature. The balloons were folded, pleatedand sheathed in a nylon sheath. The balloons were subsequently placed ina 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the following procedure. Excised pig coronary arteries (Pel-FreezBiologicals) were prepared, placed in a plastic tube and kept at 37° C.Upon removal of the sheaths from the balloon stubs, the stubs were fixedto a motor and turned at a speed 125 rpm and immersed in Fetal BovineSerum (FBS) at 37° C. for 30 seconds. The balloons were removed from theFBS (methanol was then added to the FBS at a 1:3 FBS/methanol ratio byvolume in order to dissolve the paclitaxel). Next, the balloon wasexpanded in the artery tissue at 60-80 psi for 30 seconds while immersedin regular PBS at 37° C. and after deflation and removal of the balloon,the artery tissue was removed from the plastic tube and rinsed with PBSat 37° C. After removal of the balloon from the tissue and rinsing ofthe tissue, was placed in a methanol/0.1% acetic acid solution. Theresulting methanol and acetic acid solution was tested for paclitaxelcontent using HPLC (“Drug Transfer to Tissue”). The balloon was alsoplaced in methanol and 0.1% acetic acid solution.

Example 20: Crystalline (Jar Milled Vs Sonicated) Vs AmorphousPaclitaxel

Balloon stubs (22) were coated with the hydrophilic base coat (R) andreceived a paclitaxel containing topcoat as described in Example 1. Thefollowing formulations were coated on balloon-stubs with hydrophilicbase-coat R (n=2 per formulation).

-   -   a) Paclitaxel (75 mg) was dissolved in 750 μL methanol.        Paclitaxel solution (75 μL) was mixed with 25 μL of a PEI 750        kDa solution at 25 mg/mL in ethanol. 8.8 μL of the resulting        solution was applied as top-coat on two stubs.    -   b) Jar-milled paclitaxel was suspended in water at 100 mg/mL and        thoroughly dispersed using vortex and two times probe-sonication        for 20 seconds at setting “2.5”. All of the following        formulations were prepared by weighing out paclitaxel suspension        and adding a solution of an additive such that the w/w ratio of        paclitaxel versus additive was 83:17% w/w. The resulting        mixtures were vortexed thoroughly and placed in a sonic bath for        10 minutes prior to applying the coating. 13.9 μL of the        resulting solution was applied as top-coat on two stubs.

TABLE 5 Variable Values for Example 20. Paclitaxel Added suspensionConc. Solvent of Amount water Nr. (mg) Additive (mg/mL) additive (μL)(μL) 84.8 PEI 750 kDa 20 Water (add 77.0 N/A HCl to pH 7.0) 90.6Tricaprylyl 25 ethanol 65.8 16.5 methylamine 91.5 Spermine 20 water 83.2N/A 90.4 Compound A 25 ethanol 65.7 16.5 95.3 Compound B 25 ethanol 69.317.3 90.3 Compound F 25 ethanol 65.7 16.4 96.7 Compound G 25 ethanol70.3 17.6 86.5 Compound H 25 ethanol 62.9 15.7 91.8 L-ornithine 20 water83.4 N/A 88.9 Choline•HCl 20 water 80.8 N/A

The coated balloon stubs were dried under hot air and left further todry over night at room temperature. The balloons were folded, pleatedand sheathed in a nylon sheath. The balloons were subsequently placed ina 55° C. oven for 1 hour.

Release of the paclitaxel from the coating was then assessed accordingto the following procedure. Excised pig coronary arteries (availablefrom Pel-Freez Biologicals) were prepared, placed in a plastic tube andkept at 37° C. Upon removal of the sheaths from the balloon stubs, thestubs were fixed to a motor and turned at a speed 125 rpm and immersedin Horse Serum (HS) at 37° C. for 30 seconds. The balloons were removedfrom the HS. Next, the balloon was expanded in the artery tissue at60-80 psi for 30 seconds while immersed in regular PBS at 37° C. andafter deflation and removal of the balloon, the artery tissue wasremoved from the plastic tube and rinsed with PBS at 37° C. Afterremoval of the balloon from the tissue and rinsing of the tissue, wasplaced in a methanol/0.1% acetic acid solution. The resulting methanoland acetic acid solution was tested for paclitaxel content using HPLC(“Drug Transfer to Tissue”). The balloon was also placed in methanol and0.1% acetic acid solution.

Example 21: PEI, L-Citruline. Poly-L-Ornithine and Poly-L-Glutamic Acid

Nine balloon stubs were coated with the hydrophilic base coat (R) andreceived a top-coat as described in Example 1.

Preparations for the topcoats: Jar-milled paclitaxel was suspended inwater at 100 mg/mL and thoroughly dispersed using vortex and two timesprobe-sonication for 20 seconds at setting “2.5”. All of the followingformulations were prepared by weighing out 50 mg of the paclitaxelsuspension and adding 45.5 μL of a 20 mg/mL of an aqueous solution ofthe additives such that the w/w ratio of paclitaxel versus additives was83:17% w/w. The resulting mixtures were vortexed thoroughly and placedin a sonic bath for 10 minutes prior to applying the coating. Thefollowing additives were used:

-   -   (1) PEI 750 kDa; added HCl to pH 7.0    -   (2) L-citruline    -   (3) poly-L-ornithine    -   (4) poly-L-glutamic acid

The resulting formulation (13.9 μL) was applied as a topcoat on stubs(n=3 for PEI, n=2 per formulation for other additives).

The coated stubs were dried under hot air and left further to dry overnight at room temperature. The balloons were folded, pleated andsheathed in a nylon sheath. The balloons were subsequently placed in a55° C. oven for 1 hour.

Release of the paclitaxel from the coating was assessed according to theprocedure described in example 20.

Example 22: Branched PEI with Oleic Acid Grafts and Amino Acid MethylEsters

Eight balloon stubs were coated with the hydrophilic base coat (R) andreceived a top-coat as described in Example 1. Jar-milled paclitaxel wassuspended in water at 100 mg/mL and thoroughly dispersed using vortexand two times probe-sonication for 20 seconds at setting “2.5”. All ofthe following formulations were prepared by weighing out paclitaxelsuspension and adding a solution of an additive such that the w/w ratioof paclitaxel versus additive was 83:17% w/w.

TABLE 6 Variable Values for Example 22. Paclitaxel suspension Conc.Solvent of Amount Nr. (mg) Additive (mg/ml) additive (μL) 1 92.7spermine-oleate 20 ethanol 84.3 (ethanol) 2 90.7 PEI(10 kDa)-oleate 20ethanol 82.4 2:1 (ethanol 3 89.0 PEI 750kDa-oleate 20 water 80.9 1:1(ethanol) 4 95.4 PEI(1200 Da)-oleate 20 ethanol 86.7 2:1 (water)

The resulting mixtures were vortexed thoroughly and placed in a sonicbath for 10 minutes prior to applying the coating. The resultingsolution (13.8 μL) was applied as top-coat on each of two stubs. Thecoated stubs were dried under hot air and left further to dry over nightat room temperature. The balloons were folded, pleated and sheathed in anylon sheath. The balloons were subsequently placed in a 55° C. oven for1 hour.

Release of the paclitaxel from the coating was assessed according to theprocedure described in example 20.

Example 23. PAMAM Derivatives

In this study various different PAMAMs were investigated with eitheracid (COOH) end groups or similar generation-4 amine end groups withdifferent building blocks.

The chemical formula of PAMAM 4^(th) gen—polyamidoamine dendrimer, basedon an ethylenediamine core is as follows:

Fifteen balloon stubs were coated with the hydrophilic base coat (R) asdescribed in Example 1.

Preparations for the Topcoats:

Approximately 10 mg sonicated paclitaxel (see experiment 1) was weighedout and suspended in water at 100 mg/mL. A solution of a PAMAM was addedto the paclitaxel suspension such that the w/w ratio of paclitaxelversus additives was 83:17% w/w. The resulting mixtures were vortexedthoroughly and two times probe-sonication for 20 seconds at setting“2.5” and placed in a sonic bath for 10 minutes prior to use forapplying the top-coat (applied according to procedure in Example 1).Three stubs were coated per formulation.

TABLE 7 Variable Values for Example 23 Added Conc. Solvent of Amountmethanol Num. PAMAM CAS No. (mg/ml) additive (μL) (μL) 1 Gen 4 163442-100 methanol 20 N/A 67-9 2 Gen 1.5 202009- 200 methanol 10 10 64-1 3 Gen3.5 192948- 100 methanol 20 N/A 77-9 4 Gen 4 (Dab- 120239- 100 methanol10 N/A Am-4) 63-6 5 Gen 4 (hexyl) Not 100 methanol 10 N/A assigned;Sigma Cat. No.: 640921

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were folded, pleated and sheathed in anylon sheath. The balloons were subsequently placed in a 55° C. oven for1 hour.

Release of the paclitaxel from the coating was assessed according to theprocedure described in example 20.

Example 24: PAMAM with Different Molecular Weights

PAMAM is a polyamidoamine dendrimer (i.e. contains both amide and aminegroups; see exemplary chemical structure below).

PAMAM is a globulin polymer and synthesized in generations: everyfollowing generation, as the molecular weight increased it isaccompanied by an exponential increase in number of branches. In thisexample a series of generations was tested at both 90:10 and 75:25PTX/PAMAM.

Twenty eight balloon stubs were coated with the hydrophilic base coat(R) and received a top-coat as described in Example 1.

Preparations for the Topcoats:

PAMAM solutions of generation 0, 1, 2, 3, 4, 5, and 7 with ethylenediamine core were obtained (available from Sigma) and diluted inmethanol to 50 mg/mL. Sonicated paclitaxel (see experiment 1) wassuspended in water at 50 mg/mL and thoroughly dispersed using vortex andtwo times probe-sonication for 20 seconds at setting “2.5”.

TABLE 8 CAS Nos. for PAMAM Derivatives. PAMAM Gen CAS No. 0 155773-72-11 142986-44-5 2 93376-66-0 3 153891-46-4 4 163442-67-9 5 163442-68-0 7163442-70-4

A. Paclitaxel/PAMAM formulations at 90:10 w/w ratio.

-   -   Paclitaxel (50 mg) suspension was weighed out and 5.3 μL of a        PAMAM solution at 50 mg/mL in methanol was added. The        formulations were placed in a sonic bath for 10 minutes before        it was used to apply the top-coat. Two stubs were coated per        formulation.

B. Paclitaxel/PAMAM formulations at 75:25 w/w ratio.

-   -   Paclitaxel suspension (50 mg) was weighed out and 15.9 μL of a        PAMAM solution at 50 mg/mL in methanol was added. The        formulations were placed in a sonic bath for 10 minutes before        it was used to apply the top-coat. Two stubs each were coated        per formulation.

The topcoats were dried under hot air and left further to dry over nightat room temperature. The balloons were folded, pleated and sheathed in anylon sheath. The balloons were subsequently placed in a 55° C. oven for1 hour. Release of the paclitaxel from the coating was assessedaccording to the procedure described in example 20.

TABLE 9 Tissue Transfer (μg) and Standard Deviations for Examples 16-24.Active Agent Stand- Tissue ard transfer Devi- Example Description (μg)ation Example 16 PEI-HMW/PTX 8:92 w/w in 254.68 34.51 methanol (1, 2)PAMAM/PTX 8:92 w/w in 259.80 35.47 methanol (3, 4)PEI-HMW/PTX(amorphous) 14.25 3.81 17:83 w/w (5, 6, 7) PEI-HMW/PTX(jarmilled) 17:83 149.36 19.94 w/w (8, 9, 10) PAMAM/PTX(jar milled) 17:83189.46 0.76 w/w (11, 12) Example 17 83% PTX(jar milled)/17% PEI- 120.9814.86 HMw w/w 45.5% PTX(jar milled)/9% PEI- 27.53 1.84 HMw/45.5% dextranw/w 45.5% PTX(amorphous)/9% PEI- 115.83 34.10 HMw/45.5% dextran Example18A PEI/PTX 20:80 w/w in methanol 240.53 71.69 Oleylamine/PTX 8:92 w/win 96.60 33.94 methanol PEI/PTX(sonicated) 17:83 w/w pH 76.66 17.68 7.0Example 18B Polyurethanediol 42.84 21.72 Tricaprylylmethylammonium327.84 Chloride Trimethylolpropane ethoxylate 88.42 40.25Pentaerythritol ethoxylate 20.06 7.27 Jeffamine ED-900 37.52 5.88Example 19 Trolamine 21.58 5.52 Compound C 127.06 13.55 Compound D 96.7425.54 Compound E 59.72 15.27 Linear PEI 2.5 kDa 96.46 74.25 Linear PEI25 kDa 43.88 14.20 Linear PEI 250 kDa 42.66 4.95 Branched PEI 1.2 kDa55.00 13.97 Branched PEI 10 kDa 127.70 37.87 Branched PEI 50-100 kDa177.82 41.95 Example 20 PTX/PEI 750 kDa 92:8 w/w in 27.90 2.86 methanolPTX/PEI 750 kDa 83:17 w/w jar 145.44 1.53 milled Tricaprylyl methylamine123.32 56.57 Spermine 38.10 9.87 Compound A 84.64 10.86 Compound B 47.9411.34 Compound F 44.28 8.09 Compound G 25.60 23.14 Compound H 32.66 2.57L-ornithine 52.82 1.10 Choline HCl 36.28 11.99 Example 21 PEI 750 kDa,pH 7.0 179.8 62.83 L-citruline 56.62 9.02 poly-L-ornithine 113.4 21.10poly-L-glutamic acid 34.3 6.76 Example 22 spermine-oleate (ethanol)84.08 10.74802 PEI(10 kDa)-oleate 2:1 (ethanol 41.94 1.612203 PEI 750kDa-oleate 1:1 (ethanol) 28.62 12.13395 PEI(1200 Da)-oleate 2:1 (water)63.28 9.842926 Example 23 PAMAM Gen 4 (163442-67-9) 100.89 35.93021PAMAM Gen 1.5 (202009-64-1) 31.68 11.23829 PAMAM Gen 3.5 (192948-77-9)43.24 3.178931 PAMAM Gen 4 (Dab-Am-4; 15.88 8.566633 (120239-63-6) PAMAMGen 4 (hexyl; Sigma cat. 30.68 20.23051 No.: 640921) Example 24 10:90PAMAM:PTX; w/w PAMAM gen 0 47.32 18.83732 PAMAM gen 1 57.6 16.06547PAMAM gen 2 103.22 47.60243 PAMAM gen 3 82.56 PAMAM gen 4 176.2610.15405 PAMAM gen 5 129.24 42.36984 PAMAM gen 7 123.72 17.02713 25:75PAMAM:PTX w/w PAMAM gen 0 41.54 2.008183 PAMAM gen 1 26.7 3.196123 PAMAMgen 2 58.72 4.186072 PAMAM gen 3 124.88 PAMAM gen 4 107.86 5.854844PAMAM gen 5 92.78 8.513566 PAMAM gen 7 105.92 49.78032

Example 25: Microparticles with Modified Zeta-Potential

Microparticles with rapamycin were prepared by dissolving rapamycin (100mg, available from L C Laboratories, Woburn, MA) and SYNBIOSYS™ polymer(200 mg, GAPEGCL-GALA; available from InnoCore Pharmaceuticals,Groningen, Netherlands) in ethyl acetate. The aqueous continuous phase(1% or 0.10% polyacrylic acid, available from Sigma Chemicals; in waterat pH 7) was saturated with ethylacetate 3 mL of therapamycin-SYNBIOSYS™ polymer-ethylacetate solution was homogenized (at5000 rpm for 1 minute) into 100 mL of one of the continuous phases. Theensuing mixture was poured into 500 mL deionized water andmicroparticles were isolated by centrifugation and washed 3× withdeionized water.

MATRIGEL® coated 96-well plates (Corning) were conditioned with 100 μLECM cell medium for 1 hour at 37° C. Suspensions were prepared of 11mg/mL microspheres in an aqueous solution of PEI 70 kDa (Polysciences)at 1 mg/ml or 2 mg/mL, the pH of the solutions was adjusted to pH 7 withHCl. 5 μL of the formulations was pipetted in the 100 μL medium in wellsof the MATRIGEL® coated well-plate and left for 3 minutes. All wellswere then rinsed 3 times with 200 μL PBS. Rapamycin adsorbed to the96-well surface was dissolved in acetonitrile/0.1% AcOH and quantifiedby HPLC. FIG. 10 shows the adhesion of microparticles to MATRIGEL®plates with no excipient and using PEI as an excipient at 92:8 or 83:17w/w particle/excipient ratios, and polyacrylic acid (PAA) at 1.0%/w/wand 0.1% w/w in the continuous phase.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a composition containing “a compound” includes a mixture oftwo or more compounds. It should also be noted that the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

It should also be noted that, as used in this specification and theappended claims, the phrase “configured” describes a system, apparatus,or other structure that is constructed or configured to perform aparticular task or adopt a particular configuration to. The phrase“configured” can be used interchangeably with other similar phrases suchas arranged and configured, constructed and arranged, constructed,manufactured and arranged, and the like.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated by reference. To the extent inconsistencies arise betweenpublications and patent applications incorporated by reference and thepresent disclosure, information in the present disclosure will govern.

The invention has been described with reference to various specific andpreferred embodiments and techniques. However, it should be understoodthat many variations and modifications may be made while remainingwithin the spirit and scope of the invention.

1. A drug delivery coating comprising a base polymeric layer, the basepolymeric layer comprising a hydrophilic surface; a therapeutic agentlayer forming an exterior surface the drug delivery coating, thetherapeutic agent layer contacting the hydrophilic surface of the basepolymeric layer and having a composition different than the basepolymeric layer, the therapeutic agent layer comprising a hydrophobictherapeutic agent comprising rapamycin or a rapamycin analogue; and acationic agent; wherein a ratio (wt./wt.) of particulate hydrophobictherapeutic agent to the cationic agent is about 99.9/0.1 to 90/10. 2.The drug delivery coating of claim 1, wherein the ratio (wt./wt.) ofhydrophobic therapeutic agent to the cationic agent is about 99.9/0.1 to95/5.
 3. The drug delivery coating of claim 1, wherein the ratio(wt./wt.) of hydrophobic therapeutic agent to the cationic agent isabout 99.9/0.1 to 98/2.
 4. The drug delivery coating of claim 1, whereinthe ratio (wt./wt.) of hydrophobic therapeutic agent to the cationicagent is about 99.9/0.1 to 99/1.
 5. The drug delivery coating of claim1, the cationic agent comprising a polyethyleneimine (PEI) homopolymeror copolymer.
 6. The drug delivery coating of claim 5, the copolymercomprising a PEG block.
 7. The drug delivery coating of claim 5, thecopolymer selected from the group consisting of PEG-PEI and PLGA-PEI. 8.The drug delivery coating of claim 1, the base polymeric layer furthercomprising a photo-crosslinker comprising at least two aryl ketonefunctionalities.
 9. The drug delivery coating of claim 8, wherein thephoto-crosslinker is chosen fromethylenebis(4-benzoylbenzyldimethylammonium) dibromide andbis(4-benzoyl)phosphate sodium salt.
 10. The drug delivery coating ofclaim 1, wherein the base polymeric layer comprises a hydrophilicpolymer having pendent photoreactive groups.
 11. The drug deliverycoating of claim 10, the hydrophilic polymer having pendentphotoreactive groups comprising a photo-polyacrylamide.
 12. The drugdelivery coating of claim 11, wherein the photo-polyacrylamide is chosenfrompoly(N-3-aminopropyl)methacrylamide-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamide;poly(acrylamide-co-N-(3-(4-benzoylbenzamido)propyl)methacylamide),poly(acrylamide-co-maleic-6-aminocaproicacid-N-oxysuccinimide-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamide)andpoly(acrylamide-co-(3-(4-benzoylbenzamido)propyl)methacrylamide)-co-glycidylmethacrylate.13. The drug delivery coating of claim 11, wherein thephoto-polyacrylamide ispoly(N-3-aminopropyl)methacrylamide-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamide.
 14. The drug delivery coating of claim 11, wherein thephoto-polyacrylamide ispoly(N-3-aminopropyl)methacrylamide-co-N-(3-(4-benzoylbenzamido)propyl)methacrylamideand the photo crosslinker isethylenebis(4-benzoylbenzyldimethylammonium) dibromide. 15-20.(canceled)